HOW: Stand to the side of a box/step. With the leg closest to the box/step, step up onto the surface and balance on that leg as you drive the other knee up into the air. Squeeze the butt muscles in that leg as you balance, and then step back down. The leg never leaves the box/step.
FEEL: You should feel the muscles working in the leg that you are stepping up with.
COMPENSATION: Avoid letting your knee cave in as you step up and step down. Make sure you have equal weight distribution throughout your whole foot the entire time. Avoid pushing off the ground with your back leg as you are stepping up. Don’t step down to fast – try to control it.