HOW: Get set-up with one foot behind you supported on a wall, have enough space between your foot on the ground and the wall so that your knee is not beyond your toes on the side you're standing on. With a band on above and around your knees, performing a standing clam motion by driving your knee out to the side as far as you can on the side that is supported on the wall. Make sure the knee you're standing on does not cave in.
FEEL: You should feel both hip muscles, especially on the outside of your hips working with this exercise. You will also be feeling more muscles working on the side that you're standing on throughout the entire leg.
COMPENSATION: Maintain good trunk control, do not lean side to side, do not let the knee on the side you're standing on cave in. Maintain a neutral low back position.