Proper sequencing of asanas within a practice session plays an important role in achieving maximum benefit from the session.   After a well-sequenced session, one can reach below the surface of the skin and muscles and bones of the body and get in touch with the energetic body at a more cellular level.   Then a yogic mind begins to develop.   In some schools of yoga, such as the Ashtanga school, practice sessions are arranged into vinyasa or practice series.   One famous and ancient vinyasa practiced by all schools of yoga is the Surya Namaskar or "sun salutation."

        Yoga in the Iyengar tradition does not have scripted sequences that are practiced by everyone.   Sequencing of poses is a complex and advanced topic that requires extensive study and experience with the effects of asana sequences from your own practice.   You should learn from personal experience what effect doing Adho Mukha Svanasana prior to Urdhva Dhanurasana has on your own body and mind and vice versa.   This is the experiential way of understanding asana sequencing.   Many factors influence the sequencing of asanas:   the weather, your age, your experience, how you're feeling mentally and physically on a certain day.   There are also different types of sequencing:   (1) sequencing movements within a pose, (2) sequencing from one pose to another within a family, and (3) sequencing from one family of poses to another.   All of these variables make asana sequencing a truly complex topic.

        The different categories of asanas exert different effects not only on your body, but also on your mind and emotions.   The standing poses promote emotional stability and strength.   The forward bends are calming -- even the very deepest forward bend should have a cooling effect, not a straining feeling.   The back bends are antidepressive and elevate mood.   The inverted poses increase energy and engender equanimity and a sense of well-being.   Backbends are often given to students as a prescription for depression; and forward bends as a prescription for anxiety.

        The choice of sequencing of asanas depends in part upon the state of mind you are in at a given time.   No one sequence will be appropriate for every person, for every mindset, for every energy level, for every level of experience, for every day.   Within the topic of sequencing asanas, there are a few more or less strict rules that we try to follow essentially all the time, and then there are some more or less general rules which can be broken in order to achieve specific effects.   An example of a fairly strict rule is that, in the Iyengar system, Sirsasana should be followed at some point in the sequence either by Sarvangasana, or by a similar pose to lengthen the neck such as Setu Bandha Sarvangasana or Halasana.   In the Iyengar system, we do not follow Sarvangasana with Sirsasana as is done in some other systems of yoga.

        More generally, good advice on sequencing can be thought of as general principles such as these:

          1. Standing poses are a good preparation for forward bends and also for back bends.

          2. Adho Mukha Svanasana is a good preparation for all poses and also a good warm down after both forward bends and back bends.
          There is almost never a bad time to do Adho Mukha Svanasana.   If you are doing Adho Mukha Svanasana near the beginning of a session, it is an active time, a time when you are moving into a working mode, so don't lower yourself into Adho Mukha Virasana (Child's Pose); rather step up into Uttanasana to maintain the energy of the session.   Conversely, if you are doing the pose as a warm down, it can be relaxing to rest in Child's Pose afterward.

          3. Don't alternate back and forth between forward bends and back bends.
          It is true that one good way to wind down from a session of back bends is to use a few gentle forward bends to recover and refresh the spine.   However, one way that yoga was taught in the West, especially in the early days of yoga in the West, was that you should alternate "pose and counter-pose," moving back and forth between a forward bend and a back bend to move the spine in both directions.   Generally this is not a good practice.   Generally, we devote entire sessions to a particular theme -- standing poses, forward bends, or back bends, for instance.   Even if the theme of the session includes poses from multiple classes of asanas, a strict arrangement of "pose and counter-pose" is not a skilful way of sequencing.   Generally one pose should lead you into the next pose by means of its similarity with the next pose, not by means of opposition.

          4. It is not good to sequence active or heating poses after cooling poses.
          Once you have warmed-up and begun to engage in the heart of your yoga session, if it is an active session, you will generate a certain amount of heat.   You want to maintain this heat for the duration of the active part of your session because it lends to the flexibility of your spine and body in general and keeps you mentally prepared for engaging in active asana work.   Once you begin to cool down from your session, it is not good to have any more heating or active poses.   Rather, you should gently move your body into preparation for Savasana.   That being said, it can be initially confusing as to which poses are heating and which ones are cooling.   Ultimately whether a pose is heating (active) or cooling (passive) may depend not on the pose itself, but on the level of the practitioner.   For instance, in general Sirsasana is heating and Sarvangasana is cooling, however someone with a regular, lengthy Sirsasana practice may find Sirsasana very relaxing and cooling, especially brief periods in the pose.   In general, heating poses include:   standing poses, inversions (which are cooling when done supported), arm balances, back bends (cooling when done supported), and active twists.   Examples of cooling poses include:   forward bends in general (especially seated forward bends), Supta Padangusthasana (especially cooling after back bends), Supta Baddha Konasana, and twists done gently.   Almost all poses with a Jalandhara Bandha-type chin lock (e.g. Sarvangasana, Halasana, Setu Bandha, and Viparita Karani) are cooling to the brain and body.   After doing poses in which the chin is in Jalandhara Banda, no more active poses should be done because these are definitely cooling for the body and brain.   Progress from these poses on to Savasana.

          5. Generally after a deep forward bend sequence consider doing a few twists to balance and release your spinal muscles.
          However, try not to end your practice with a twist due to the asymmetric feel it may leave in your spine.   Follow any twisting at the end of your session with at least one symmetric forward bend like Pascimottanasana to resolve the tension in your spine before relaxing in Savasana.

          6. It is especially important to warm-down skillfully from an active back bend session.
          Active back bends exert strong work on your body and you need a plan to bring your body back into a neutral mode and then down from there to the point of relaxing in Savasana.   A good pose to begin warming down from active back bends with is Adho Mukha Svanasana with your hands and feet placed wider than you usually have them.   A wide Adho Mukha Svanasana after backbends fills out your back and softens your kidney area.   However, remember to keep your low back relatively convex now in Adho Mukha Svanasana to relax it -- you don't want to accentuate any concave curve there as you might do in this pose under other circumstances -- you are recovering from back bends and you need to respect the work your back has done.   A next good choice for back bend warm down is Adho Mukha Virasana (Child's Pose) done on the support of bolsters or blankets under your torso.   (You could also then use the bolsters or blankets and do a supported Upavistha Konasana or supported Janu Sirsasana).   The important thing is that it is not skilful to move directly into a deep forward bend directly after active back bends.   Try these other poses first.   Then, you might try some gentle Uttanasana (often we do Parsva Uttanasana, moving slowly back and forth from one leg to the other leg) to place some stretch into your low back muscles.   After a backbend session, light, lengthening twists are good, but you should do no deep twisting and do not hold them for a long time.   (Also in twists following back bends, do not arch your spine, because that is what you've been doing all along in the back bends.   Rather draw your abdomen inward and don't concave your low back.)   Other poses that help release your back muscles after back bends are Supta Padangusthasana and Ardha Halasana on bolsters or blankets placed on the seat of a chair.   Ardha Halasana especially will help calm and cool your nervous system after active backbends.   Finally after backbends, regular Savasana is often not the best choice for a final resting pose.   In Savasana after back bends, it is often better for your back to do have your legs (calves) up on a chair or to put a bolster under your knees to allow your low back to release fully onto the floor and be supported by the floor.   If you have a bolster under your knees, still make sure your heels contact the floor (or put them on blocks) to have that contact (Skt. sparsa) or sensory feedback.   After back bends, you might even consider doing prone Savasana, lying on your abdomen instead of your back with your heels pointed out to the sides.

        Although, again, there are not strict rules governing the order of asanas within a session, some general principles can be used to allow the asanas to work more effectively together.   If you were going to do poses from each of the asana classes (which is not something we necessarily always do), a good overall sequence for a practice session would be:

          1. Standing poses
          2. Back bends
          3. Forward bends
          4. Twisting asanas
          5. Inversions
          6. Restorative poses and Savasana

        You can vary this sequence.   Much depends upon the specific effect you are trying to get out of your session.   For instance, moving inversions earlier in the sequence would be good when you plan to expend a lot of energy on inversion variations since you have more energy near the beginning of your practice session than toward the end.   Another common sequence is:

          1. Standing poses
          2. Arm balances (especially Full Arm Balance)
          3. Inversions
          4. Back bends
          5. (Forward bends)
          6. Restorative poses and Savasana

        In general, the early months of your yoga practice should be devoted primarily, though not exclusively, to the standing poses to build strength and flexibility in the legs, especially the hamstrings, and to open the hip flexors which often limit pelvic mobility.   When you are mature in the standing poses, that is a natural time to begin focusing on the seated forward bends.

        Within a standing pose session per se, it is generally good to sequence them in an order such as this:

          1. Lateral bends (e.g. Trikonasana, Parsvakonasana)
          2. Backbends (e.g. Virabhadrasana I)
          3. Twists and rotations (e.g. Parivrtta Trikonasana)
          4. Forward bends (e.g. Uttanasana)

        It is also appropriate at any point to use Uttanasana between any of the standing poses as a "neutral gear" to assimilate the effect of the previous pose and prepare for the next one in the sequence.   Prasarita Padottanasana is often done at the end of a standing pose sequence because the head is resting downward and the pose is quieting, too much so to sequence this pose in the middle of an active sequence.

        It is often fun and challenging to develop standing poses vinyasas in which one pose flows into the next.   Of course, you hold each pose for some duration once you have established it and try to maintain the pose with equanimity before moving on to the next one in the sequence.   An example of a long standing pose vinyasa might be:

          1. Tadasana, jump your legs apart and move into:
          2. Trikonasana to the right, walk your right hand forward and move into:
          3. Ardha Chandrasana on the right, turn your torso toward the floor into:
          4. Virabhadrasana III, reach back and ground your left leg into:
          5. Virabhadrasana I, turn your hips leftward into:
          6. Virabhadrasana II, bend your torso forward into:
          7. Parsvakonasana to the right, rotate your torso into:
          8. Parivrtta Parsvakonasana, walk your left hand forward into:
          9. Parivrtta Ardha Chandrasana, reach back and ground your left leg into:
          10. Parivrtta Trikonasana, join your hands behind your back and move into:
          11. Parsvottanasana to the right, turn your torso around to the left into:
          12. Prasarita Padottanasana, continue turning your torso leftward into:
          13. Left Trikonasana, (and then repeat the sequence on the left)

        After the sequence is finished on the left, jump your legs together after Prasarita Padottanasana to move into Uttanasana and then stand up to finish in Tadasana.   You could devise hundreds of such standing pose vinyasas, selecting different poses to emphasize and performing them in different sequences.

        Here is a shorter example of a standing pose sequence:

          1. Tadasana, jump your legs apart and move into:
          2. Trikonasana to the right, rotate your torso into:
          3. Parsvottanasana over your right leg, then continue to rotate your torso into:
          4. Parivrtta Trikonasana to the right, rotate back into:
          5. Parsvottanasana over your right leg, then finally rotate your torso back into:
          6. Trikonasana to the right (and then repeat the sequence on the left)

        Here is an excellent medium-length standing pose vinyasa:

          1. Tadasana, jump your legs apart and move into:
          2. Trikonasana to the right, bend your knee into:
          3. Parsvakonasana to the right, raise your torso into:
          4. Virabhadrasana II to the right, turn your hips into:
          5. Virabhadrasana I to the right, lenghthen your torso over your front leg into:
          6. Virabhadrasana III, lower your right hand to the floor and rotate your body up into:
          7. Ardha Candrasana on the right side, lower your torso toward your right leg for:
          8. Urdhva Prasarita Ekapadasana, step your left leg back to the floor into:
          9. Parsvottanasana (place your hands in Paschimanamaskarasana),
          10. Look up and raise your chest, turn your feet parallel and your torso to the front, and then repeat the sequence on the left

        Here are two good, general restorative sequences:

              1. Supta Baddhakonasana
              2. Supta Virasana
              3. Adho Mukha Virasana on a bolster
              4. Adho Mukha Svanasana with head supported
              5. Uttanasana
              6. Sirsasana
              7. Chair Viparita Dandasana
              8. Chair Sarvangasana
              9. Chair Halasana
              10. Karnapidasana
              11. Setu Bandha Sarvangasana with support
              12. Viparita Karani
              13. Savasana

              1. Paryankasana on bricks to open your chest
              2. Adho Mukha Svanasana with your head supported on blankets
              3. Uttanasana with your head supported on blankets or blocks
              4. Sirsasana for about eight minutes
              5. Sarvangasana held for at least the same length as Sirsasana
              6. Halasana
              7. Block Setu Bandha, feet on the wall
              8. Viparita Karani
              9. Savasana II with some ujjayi pranayama
              10. Savasana

        Of course, not every session will include every type of asana.   Some sessions may be devoted to a single asana.   In fact, is worthwhile to devote one session per week entirely to restorative poses, or entirely to Viparita Karani.   If you devote a session entirely to standing poses, the ideal time to do that would be in the morning or the daytime, rather than late in the evening, since they are energizing poses.

            One good approach to learning asana sequencing is to practice class sequences arranged by knowledgeable teachers.   Examples of asana sequences can be found in these books:

              Yoga The Iyengar Way, Silva, Mira, and Shyam Mehta
              Yoga: The Path to Holistic Health, B.K.S. Iyengar
              Yoga: A Gem For Women, Geeta Iyengar

            Many changes in Mr. Iyengar's sequencing ideas have occurred since the publication of Light on Yoga when the photographs of Mr. Iyengar were taken in his late 50's.   As such, the sequences in Light on Yoga should be viewed more in their historical context, and as advanced, orthodox sequences, not as examples for daily practice for the typical modern yoga practitioner.