To practice this exercise, which is known as Savasana or Corpse Pose, lie on the floor. Turn the palms of your hands upward (this position will help to induce a feeling of relaxation and of mental receptivity). The head, neck, trunk, and legs should be in a straight line. Do not use a pillow in this position; the flow of blood should be equal to all parts of the body.
There are many parts of the body that are tense without our conscious knowledge. How are we to become enough aware of them to relax them? The answer is, by increasing the tension throughout the body. The best way to induce preliminary relaxation in the body is first to inhale, tense the whole body, then throw the breath out and relax the entire body at once.
After this preliminary relaxation (which you may repeat two or three times), lie very still. Be aware of your breath, if you like. You may watch it in the nostrils, or simply be mentally aware of the rhythmic rise and fall of your navel. As your calmness deepens, feel your consciousness becoming centered increasingly at the point between the eyebrows.
Now, strive for deep relaxation. Think of your body as surrounded by space — space in all directions spreading out to infinity.
Now think of your feet, and visualize this space gradually seeping through the pores of the skin into your feet, until your feet become space. Visualize this space as gradually coming up into the calves, thighs, hips, the abdomen and stomach, the hands, forearms, upper arms, shoulders, chest, the back of the neck, sides of the neck, the throat, jaw, tongue, lips, cheeks, eyes, and brain.
In feeling space in your brain, release from your mind all regrets about the past, all worries about the future. Rest in the infinite ocean of the eternal Present. The objects of endless human concern no longer exist. There is nothing in all eternity but the Right Here, the Right Now.
Bones, muscles, movement I surrender now; anxiety, elation and depression, churning thoughts: All these I give into the hands of peace.
If you practice yoga postures, savasana may be practiced briefly between other postures, until the heartbeat and the breathing have returned to normal. At the end of your posture session, however, one should go into deep relaxation in Savasana for at least five or ten minutes, or until you have felt the deeper rejuvenating effects of total relaxation.
You can also use Savasana to relax a particular part of the body. If you have been stretching a certain body part for example, and are finishing with Savasana, concentrate especially upon the relaxation of that part, rather than on the relaxation of the whole body.
Savasana brings supreme relaxation; helps in the development of receptivity, so important to yogic practice; rejuvenates the body cells; and aids in mental and physical healing.
The Ananda Course in Self-Realization by Swami Kriyananda