HOW: Stand by something you can grab onto that doesn't move. Bend your knees as you look up and squat down. Then look down as you straighten our body all the way out and push into the ground raising your heels off of the ground. Go back and forth doing these motions for the prescribed amount of reps.
FEEL: You should feel muscles in your lower body and neck working.
COMPENSATION: Make sure to do the right order of putting tension and slack on the nerve.