If he is doing it to be naughty or nappy do a couple of tight circles to keep him moving. When he is forward then carry on.

Does he do it with company or on his own?

Jake my horses whois also a section D and is 15YRS OLD!!!! Is very nappy on his own and spins around and runs off. I take a schooling whip with me and he always spins right as the hedge is always on the left. I keep whip in right hand and if he goes to spin I just place whip by head so he can't turn. He also rears up to get his way and I just take one rein and pull and do a circle so he aint on hind legs.