With an appy that the lady I ride with has, she does a lot of walking and then stopping with her from the ground. She's a major boss mare, so she will try to push and she's been getting better since we've been doing this with her. Just making her stop every time you stop. So, take a few steps....stop. Take a few steps, stop. If she pushes past you, she has to go back and start over. Ex: if she was being taken to her stall to eat, or being taken back out to the pasture. With staying still, I usually just won't let them go til they stand willingly, then give her her head and let her go forward. Practice a lot of transitions and such so that she's paying attention to what YOU want.
A horse is the projection of peoples' views about themselves--strong, powerful, beautiful--and it has the capability of giving us escape from our mundane existance.