My old barrel pony wad always really hot. Walking him helped alot and he also did good when you kept him busy (transitions, circles, etc...). Other things that seemed to help were just taking him out and hanging around with him (not even saddling up) and keeping him with another quiet horse.
I'm a quiet rider so I get thrown all the hot horses. A quiet rider reallly helps. Also the feed could have something to do with it. Also if your horse is somewhere where he can't get much energy out like a stall.
I have seen some hot horses respond well to a quiet "hugging" leg, in other words they have taught the rider to fear applying leg. Work with following hands patiently in shoulder in / shoulder fore so your inside leg asks for the movement - following patient hands, let the leg do the work and it does sometimes calm the horse. Don't demand a lot of angle, a little is good and reward often. Good luck.
You have to get them working really hard and paying attention to you. This means really getting them using their hind end, and changing up exercises very freaquently. This will keep them occupied and thinking, and focusing on you. This will make it so they don't have time to think about running away, or paying attention to their sorroundings.