Making yourself smaller works well, and feeding treats is my total favorite. Once you teach her to eat a treat (I've gotten horses who have NO clue what a treat is, or to eat from a human hand), then I make sure to keep some kind of treat right beside the stall. Everytime I go to the stall, I hand the horse a treat and walk away, 5, 6, 7 times/day, until in just a few days usually, she comes to the door BEFORE you get to it to get her treat. Then I make sure she lets me pet her for her treat. Pretty soon, she is liking the attention as much or more than the treat, and you can start being random with the treats. I can stand in the pasture and holler, "Who wants a treat?" and the whole bunch come running.