In the beginning stages of practice, Wing Chun stepping is awkward and difficult for new students to do correctly. One way I found tonight to help students overcome a variety of problems such as over-stepping with the backleg, not keeping the toes parallel, and not keeping their hips facing forward is to apply pressure on their forward extended hands as you step backwards with them at the same pace. (picture to come)
This will give them the opportunity to feel when their structure is rooted and the benefits of keeping hips parallel to increase stability as well as to experience being linked. At the same time it lets you monitor their feet to make sure they are parallel.
As one of my students (a former wrestler with boxing experience) started getting the hang of it, I weaned off the pressure and made him transition to punching at about 150% improvement.