Aside from cardiovascular (aerobic) exercises to strengthen the legs, sounds like you need to increase "awareness" of foot position. Ballroom dancing could do it, along with such things as running sideways or stepping through a tire obstacle course. Here's one that's a little more dangerous: walk quickly up or down stairs while turning in circles! You'll learn the value of foot awareness doing that. In your spare time do things like "writing" the alphabet with a dangling foot.