My horse has been training me...to make the reins longer, to let him canter flat, to let him stop paying attention when he's distracted by people outside.
Silliness aside, my horse does currently fill that capacity. On any given day, he says, "I don't want to trot on contact", so that's what I learn to make him do that day. I just bought a truck and trailer, so my professional training budget is somewhere between goose-egg and nada.