In my last lesson, my coach said: "And on the short side, improve the trot!" -- coming out of a shoulder in, making sure I re-energized the trot. Now this may not seem remarkable. I'm sure you've had hundreds of lessons where your trainer tells you to kick something up a notch in more or less generic language. The remarkable thing here is, that I earned that generic language!
While it is frustrating to many students to be told what to do, but not how to do it (or at least not how to do it correctly), my coach spends loads of time on getting the ABCs installed in the riders. So that when XYZ, i.e. something that needs to be executed without detailed how-to instructions, is asked, they have a fighting chance of getting there. I've spent the better part of last year backtracking on my ABCs. So when I got the "now improve the trot" without the "make sure your this, that, and the other is in place" -- and I knew what to do to produce the desired results within a stride or two, I realized just how much the presupposed vocabulary in our conversation had evolved.
A couple of years ago, when told to "improve the trot", I would have had a vague notion of "more trot". To accomplish that, I probably would have kicked the horse forward a bit and because my seat wasn't all that great, had to use quite a bit of rein to keep things in oder. And that is highly likely to have upset the balance of the horse rather than improved it.
In my lesson, I had a very clear idea of what I needed to improve the trot, namely more engagement, i.e. more bend in the haunches. So now that my seat is generally in a pretty good place (i.e. my alignment is correct, my core is engaged, my spine is in neutral, my thighs are rotated and letting the toes point forward, my seat isn't too flat anymore etc.) , I can squeeze a bit with my lower legs for the forward while keeping it contained with my thighs, really dome my pelvic floor to bring up my horse's back (and often it is one side more than the other). And instead of kicking, I can push a little with my lower leg on the inside and suck her up with my seat so that when she is stepping further under her center of gravity with her inside hind, she also comes up in her shoulders and wither, and grows taller and straighter underneath me. Then I can give my hands forward to make sure I have her continually reaching for the bit.
Yeah. That actually happened. ;) Here's to becoming a walking (or riding) encyclopedia of dressage.
