Astavakrasana (Eight-Angle Pose)
With your ankles crossed, increase the pressure of your right inner knee on your arm, as if you were trying to push your shoulder toward the floor. Resist the force of the knee on the arm by pressing your right hand into the floor and pushing your upper arm back against the knee. This action will ensure that your arm and shoulder don't collapse despite the extra pressure of the leg. Keep pressing with your right knee and begin to extend your right leg by lifting your right foot away from the floor and reaching out through the right inner ankle.
Since your ankles are crossed, when you extend your right leg, your left leg will begin to stretch as well. Roll your left thigh inward as you did in Eka Hasta Bhujasana and ground the femur deeply into the back of the thigh. Squeeze your right arm between your two knees, pressing your palms firmly into the floor; lift your torso and straighten your left arm as fully as possible. Your right arm will remain slightly bent. This intermediate position will develop your balance and stability. Some of you may find it more difficult than the final pose.
After a couple of breaths, exhale and slowly bend both elbows, gradually lowering your chest and head toward the floor until your shoulders are level with your elbows. Press firmly with the mound of your thumbs to activate the muscles in your wrists and arms and control your descent. As you lower your torso, lift your hips so that your tailbone is level with your breastbone.
Take care not to sink into your left shoulder. Although your legs are on your right arm, your left arm has to work harder to keep you from collapsing. Draw your shoulder blades toward your kidneys and lift your head, taking care not to compress your neck.
This pose gives a good twist to the lumbar spine. To deepen that twist, stretch your outer left thigh from your hip toward your knee and simultaneously turn your navel toward the left.
After several breaths, exhale and press back up to the straight arm position. Then uncross your ankles, swing your left leg out in front so that you are back in Eka Hasta Bhujasana.
Slowly lower yourself back to the floor, remove your right leg from your arm, and return to Dandasana. Then repeat the whole sequence, from Eka Hasta Bhujasana to Astavakrasana and back again, on the other side. (Use the same approach, starting from either sitting or standing, on both sides.)
Graceful Exits & Entrances
Coming into Astavakrasana from Eka Hasta Bhujasana is the simplest way to learn the pose. While there are several more challenging approaches, these techniques should only be tried after you have mastered entering from Eka Hasta Bhujasana. This is literally a "look before you leap" strategy, because one method is to jump into Astavakrasana from Adho Mukha Svanasana. To prepare for this, you can practice coming into Astavakrasana from Tadasana, just as you practiced coming into Eka Hasta Bhujasana.
To learn to jump into Astavakrasana without the feet touching the floor, I found it helpful to start from a short Dog Pose—Chihuahua size—so that I began somewhere in between Uttanasana (Standing Forward Bend) and Adho Mukha Svanasana, but leaning more toward Uttanasana. If you jump from too far back before you develop control, the weight of your body hurtling forward and landing on one arm may strain or injure your wrist, elbow, and/or shoulder—not to mention the possibility that you'll land on your nose.