The most basic standing posture in yoga, Tadasana (Mountain Pose), can help you find alignment. This asana is the foundation for all other poses, because it teaches you correct alignment and can be excellent practice for improving posture and strengthening the lower body.
Stand with the bases of your big toes touching and your heels slightly apart. (If you feel unsteady, bring your feet hip-width apart.) Lift your toes and fan them out onto the floor without gripping. Feel the soles of your feet connect with the earth as you invite energy to rise up your legs, firming your thigh muscles and lifting your heart. As you root down through your feet, let the top of your head extend toward the ceiling, lengthening your spine and releasing your tailbone toward the floor. Gaze softly toward the horizon, with chin level and face relaxed. Drop your shoulders away from your ears and bring your palms together at your sternum—the heart center. Take several slow, full breaths.
You can practice this pose anytime during the day—try it out while waiting in long lines!