I worked with several instructors who had me try different things...
- Start posting
- Stop gripping
- Make my seat heavy
- Make my seat light
Then someone, a friend, said "When you want him to trot, just think TROT."
It worked. Don't ask me how. Maybe I made some minute unconscious body adjustment as I thought "TROT." I think it must be partly that. But that sensitive thoroughbred Harv was just a tuned-in kind of horse. It really seemed like he heard me. It helped us synch up.
It's a technique worth trying, at least for transitions (can't imagine it would work for a leg-yield!). But canter-halts, canter-walks, trot-halts, halt-trots? Maybe.
Try thinking it, and let me know if it works.