Horses understand action. So when my horse pins his ears back or acts disrespectfully towards me in any way, if I put pressure on him and reprimand him for this behavior, he soon figures out that it was uncomfortable for him to do that. Horses get away with whatever you allow . If you let your horse be disrespectful and act like an idiot, believe me -he will do an excellent job of just that. If you let your horse act respectful, patient and obedient, he will very quickly be respectful, patient and obedient.
Horses learn through repetition .
When you do something to a horse once, you plant a seed. When the horse does it again, it becomes a habit. If it is a good thing, it is a good habit - if it is a bad thing, it is a bad habit. You either have a respectful horse or a disrespectful horse. The more black and white you can keep it, the easier it gets.