a school horse is a good idea, I think.
As for the hands, all of those things take time to become ingrained habits. No one I know got it overnight. Here's something to help:
Think of your hands as kind of holding the bit ring itself. To do so, they would have to be vertically aligned. AND thing of your thumb as being the "roof" on top of your closed and bent fingers. AND the roof POINTS directly toward the horse's bit, like laser sights out of your thumb toward it.
Get it, and KEEP it , as long as you can. Then REget it and so on . . . ..