HOW: Start by standing with your feet about shoulder width apart. Bend your knees, hinge forward slightly at the hips and squat down to a comfortable position. While holding this squat, push into the ground with your toes and raise your heels off of the ground for the prescribed amount of reps.
FEEL: You should feel your thigh and calf muscles working.
COMPENSATION: Maintain the squat as you perform the heel raise. The heel raise should lift your whole body up.