HOW: First tie a band around a sturdy anchor. Then place the looped part of the band around the front part of your forefoot. With resistance on the band, slowly bend your ankle upwards towards the sky and towards you. Then slowly lower it. The further you are away from the anchor point, the harder the exercise.
FEEL: You should feel the muscles on the front part of your lower leg working.
COMPENSATION: Try your best not to also extend/move your toes. Try only move the ankle joint.