Let's talk about teaching The Varsity Drag!
Flaps should begin from a ready position with the foot relaxed and the knee lifted. Brush the foot forward and step onto the ball of the foot, shifting weight completely and releasing the opposite foot so that it is ready for what comes next. Although the flap is a wonderful traveling movement, keep the action small so that the foot does not get ahead of the body, and be sure that all sounds are ball-tap sounds.
Check out the video below for a demonstration!