• Wear comfortable clothing in which you can move freely; It's best to practice barefoot.
• Ideally, practice on an empty stomach: try not to eat 2-3 hours before practice.
• Practice in a well-ventilated room that is neither too hot nor too cold.
• Always do a few warm-up movements, combined with deep breathing, before doing the hatha yoga poses.
• If time is short, remember that it is better to do a few postures slowly--and deeply-- than to do many of them hastily.
• Never strain or struggle to get into a pose. Move into and out of the postures gently, smoothly, and with awareness. Do not push through tightness; it's much more effective--and much safer--to relax it away with awareness and with the breath, thus facilitating a deeper opening.
• Use common sense: Honor contraindications suggested for the poses and breathing exercises, even if you "feel up to it." ("Contraindication" comes from "contra," which means against, and "indication." It refers to a condition, usually physical, that indicates one should not do a particular asana or pranayama).
• Never compete: Don't expose yourself to injury by competing with others--or with yourself. Pride of body or of superior flexibility have no place in yoga. Progress in yoga is not absolute, but directional--it's a matter of taking your own next steps.
• To the best of your ability, breathe diaphragmatically while holding an asana, unless the asana calls for a different, specific type of breathing.
• In all poses, avoid swayback (over-arching the lower back) by tucking the tailbone when necessary to lengthen the lower spine. In some cases, contracting the lower abdomen seems a more natural movement and will accomplish much the same thing.
• Remember that your neck is part of your spine. Keep it in line with the rest of the spine to avoid compressing the cervical vertebrae or discs.
• Avoid twisting your knees; they're hinge joints, made to fold with little or no rotation.
• Avoid tensing the shoulders; keep the back of the neck extended and the shoulder blades released down the back.
• Standing poses: Do not hyperextend the knees (i.e., don't push back on the kneecaps, "locking" the knee). If you have this tendency, either pull the kneecaps up by engaging the quadriceps muscles, or keep the knees slightly bent.
• Standing poses with knee bent: When one leg is supporting most of your weight, never allow the knee to go beyond the ankle. Keep it over the ankle (lower leg vertical), or for extra protection, slightly behind the ankle (i.e., don't come down so far into the pose).
• Forward bends: Keep the spine long and fold at the hip joints. It's okay to let a healthy spine round slightly, but only through relaxation and with complete awareness, a long spine, and no discomfort. Avoid entering or exiting the pose with a rounded spine and straight knees, as this can compress the intervertebral discs and pinch the spinal nerves. For the greatest degree of safety, keep the knees slightly bent throughout the pose.
• Backward bends: Protect the lower back (lumbar spine) by tucking the pelvis (i.e., lengthening the tailbone downward), releasing the shoulder blades away from the ears, and lifting through the sternum/heart area. Let the curvature in the neck match (or be less than, if your neck needs support) the curvature in the rest of the spine.
• Sideways bends: Keep the underside of your rib cage open so as not to close off your breathing or overstretch the lateral flexor muscles of the spine.
• Twisting poses: Keep the spine lengthened as you exhale into your twist. If the spine begins to round, back off a little from the twist. This helps prevent compression of the spinal discs and nerves, and keeps the life force flowing freely.
• Inverted poses: Never put undue weight or stress on the neck, and do not remove the natural curvature of the cervical spine. If your arms and shoulders are not strong enough to bear the weight of the body, then it's best to practice simpler variations of the inverted poses until you're able to do the classical versions.
• Sitting poses: When entering the cross-legged positions, be sure that all rotation occurs in the hip joint, not in the knee. The lotus pose, or even the half lotus pose, is not for beginners unless their hips are already very flexible.