Some basic stretches that help loosen the body in preparation for yoga practice are:
Neck roll - move neck from side to side in gentle semi-circular motion
Shoulder roll - rotate shoulders back and forth, connect elbows from behind
Knee roll - feet together, gently bend knees and rotate left and right
Wrist roll - flex wrists up, down, sideways; stretch, fold fingers into fist, release
Thigh flex - cross left thigh over right, turn upper body to left; reverse sides
Ankle flex - move ankles up, down, sideways; stand on toes, then on heels
Side stretch - heels together, toes apart, arms overhead; sway torso sideways
Back stretch - hands on buttocks, knees together, inhale deep and lean head way back
Forward stretch - hands on hips, knees slightly apart, exhale fully, fold from hip
Body balance - twine fingers, turn palms out, raise arms high, stand on tiptoe