Stand with your feet a few inches apart, with your right foot on a plastic lid, glider disc, or paper plate. Make a fist with one hand, and cup your other hand over it. Keep your hands in front of your chest throughout the exercise to help you stay balanced.
Put weight into your left leg, and as you slowly bend your left knee and squat down, slide your right foot out to the side. Then as you slowly straighten your leg, slide the right foot back in. Most of your weight remains in the leg that's not moving.