I'm nervous about commenting because I am such a new rider (9 months now), but I have been riding a very well trained horse, and this is what he taught me! I have been recently working on slowing down the trot without using the reins at all. We started with a walk -- I would urge him to a faster walk with my legs and seat, then slow the walk by easing my leg pressure, sitting back and forcing my weight back and down. After he did this well several times, we went to the trot and did the same thing. At first I had to really overexaggerate this (or at least it felt like I was overexaggerating it), and take my legs completely off him, but it really did work well. If he slipped down into a walk I would just put my legs back on a bit. I assume that this would work at a lope as well? Forgive me if I am completely clueless.