HOW: Get set up standing holding a band in your hand while making a fist with your elbow relatively straight. Support your arm with your other arm above your elbow against your body. With your thumb facing up, perform the exercise by cocking your wrist up against the resistance, go as far as you can, lower your wrist down as far as you can tolerate and repeat.
FEEL: You should feel the muscles on the top of your wrist and forearm on the thumb side working with this exercise.
COMPENSATION: Try to maintain arm position and only move at your wrist/hand. Be sure to keep a strong fist.