Join Date: Sep 2011
Location: Germany- but not German =D
Half halts, stopping, transition work will help. Do this in walk and trot. You don't /have/ to canter every time you ride, so work up to it, make sure the horse is nice and relaxed under you, and you shouldn't be using your reins to stop and pull him back, that should come from your seat and legs. If you use your hands, he'll just pull against you and use his neck like a fifth leg.
If he does tank, use your inside leg, and bring your inside hand over your thigh, bringing the outside hand for slightly and turn him on a tight circle, he'll drop out of the canter.
You need to use your inside hand to control the speed, don't use half halts too fast, let him feel them, and sit back, and sit back again, and work him on a circle.
Hope this helps!