I warmed Harley up in the standard fashion - ten minutes or so on the line, another ten or so with the neck stretcher. I think it's near time to shorten that again, since he's found loose/relaxed, either from stretching the elastic out, or found a slight release without being 100% correct. Time to Up the Difficulty!
I hopped aboard with a game plan, again. Fortunately, Harley consented to the game plan. The wind was HOWLING out of the SE, 30+mph gusts - yay Texas Spring (NOT). We went through our standard walk/halt/walk/halt routine. I settled into some good steady-eddy halts, and flexed him side to side to side, repeatedly. He's flexing slow but light heading right, but that left leaves just a few inches short without me fussing at him.
Then I made the game more interesting. I walked him in a rather tight circle, holding only the inside rein, adding outside leg. When he bent in his middle at the ribs, and flexed his head at the poll, nose in and towards me, I'd release and walk straight a few steps. We did this three or four times left, three or four times right, then I'd ask for both reins collected, and head straight. When I got a handful of solid steps accepting the pressure, I'd release.
It took quite a while (a solid twenty minutes), and I got a bit dizzy trying to watch him, and where we were going, turning in those tiny circles, but he seemed to be getting the idea. Clinton Anderson does this bending exercise at the trot, but it always looks to me like it's forward disengaging hind quarters, rather than bending at the ribs, and positioning the neck/head correctly. I concentrated at the walk on Harley's back, and felt the correct back-lifting when he moved correctly on the bending circles. We're getting there. It's slow, but we're getting there.