Normally, I'll give treats after a ride or groundwork session, sort of as a reward for good work, and combined with petting and rubbing of ears (Scout's favorite spot
), or at the end of the day when I close up the barn for the night. My sis's QH had a leg injury that's requiring Dad's help to bandage (need 3 people, 1 to bandage, 1 to hold the extra light, and 1 to hold and pacify the horse), so her horse hates Dad right now because the leg is tender. Dad goes back and "buys" Rio's good humor back with carrot cookies so he doesn't get creamed next time.
Scout isn't terribly food motivated... a verbal "good boy" and a rub on the neck, forehead, or withers does wonders for him. He doesn't go bananas a "cookie" time either, like Rio will, grumbling and bobbing his head for more.