HOW: Stand on one leg facing a wall while on a foam pad. While balancing on that leg with a slight bend in your knee, toss the ball into the wall and play catch with it. Keep your hips facing forward as you throw the ball. The farther you are away from the wall the harder it will be.
FEEL: You should feel your lower leg and foot muscles working.
COMPENSATION: Keep your hips facing forward, don’t rotate your whole body while throwing the ball.