HOW: Start by holding a long towel while standing fairly close to a wall to the side of you. Have your feet about shoulder width with your knees slightly bent. All in one motion, hinge forward at the waist while bringing the towel down and away from the wall. From here, push into the ground with that outside leg and begin to whip the towel into the wall with your momentum going towards the wall.
FEEL: You should feel your leg and core muscles working the most.
COMPENSATION: Make sure to keep your hips perpendicular to the wall even while whipping the towel.