A fun game for kids who are working on this is "hunt the rabbit". As they ride behind you ( the rabbit) have them pretend they are holding their rifle and trying to keep the rabbit in the sights. When you make your toeside turn she has to follow you with her rifle. This will forced her to lead with her front shoulder. If she maintains keeping you in her sights and completes her turn, she yells "bang" and you get to fall down.
that is genius!!