We stand at the gate with a white bucket of grain and shake it...once the horses come and are haltered, they get a bite. It might not be the best method, but the white bucket is responsible for saving a run away. I hauled a teenage girl and her leased horse from our farm to a 4-H ride and the horse slipped away. Thanks to my husband's very quick thinking, he grabbed a white bucket from the trailer that had a couple of brushes in it and shook it, just as the horse was making a run for the road. The horse heard the rattle, saw the white bucket and turned and walked up to him like he does in the pasture every day.
Yeah, we call it the bribery bucket, but whenever a horse gets out of their stall, pulls away from a handler, etc, the bucket comes out, and the horse only gets the grain when they are back where they belong (stall, hitching rail, etc.).