From the ground, what gidget said. I stand beside the head facing her rump, take the lead rope close to the clasp, and move it backward toward the neck and touch her under her chin. I say "back." To teach her, I took a quirt and gently tapped her on her upper legs. The second she moved back I released and praised her. Then repeated. I also did this from both sides.
From the saddle. Some horses will respond to slight leg pressure and equal pull with both reins, but not all. Christy was confused, to her I was saying whoa, but at the same time telling her to go
. So, I very gently pull on the reins seperately. First a little pull on the right, then release the right and a little pull on the left, back and forth (see saw, very gently) along with slight leg pressure. I sit up in the saddle telling her I want her to move. This works for us.