I'm just learning canter, and it tends to go fine at first but then the horse speeds up, usually because the other horse is. My trainer says grab mane, but I think that's when it goes south. I then lose rein contact and then hold on with my legs, and they go faster, etc. So I'm thinking if I can keep my reins and just try to keep the canter slow? I love it when it's slow, but I've fallen of a few times when they speed up, so it's hard not to panic when they do.