It's just using the correct aids at the correct time in the correct order, that's all

We had a great dressage lesson today, with a little something new.  John has very gradually increased the independence of each aid (each hand, each leg, seat), and today we not only used each leg independently, but with different strength, and used a hand giving an aid in two directions at once.
At the canter, I had left leg back (outside leg) and inside leg up next to the girth, and I was using both legs to ask him to go forward, but I was using the outside leg Harder, so that he didn't bulge out of the circle.  I was able to do it, but it was definitely a novel experience.  With my hands, I was using outside hand not just to half halt, but also to move diagonally towards my inside hand to help steer his shoulders.
So first, we worked on steering on the circle, and using an open inside hand to not just bend his neck but to move his shoulders in.
He was crabby (he started the day crabby in his stall), and was stiff, so we ended up having to use outside counter bend to get him to loosen up.
John was watching me warm up, and I let Duke go around with his neck all stretched out and John said that's ok for the very beginning of the warm up, but if it were up to Duke, he'd do that all the time, so I need to get him to work after just a few laps.
We did 10 meter circles, but worked on the transition between two circles being round around my leg, not jerking his face and neck around to make the second circle.
We also worked on getting him a bit more forward, once he was bent and moving nicely, then asking him to step under himself a bit.  This, I think, was the hard work, because he got quite sweaty, even in his butt.  John said that he was working much harder with his hind end than a few months ago.
John said whichever rein is the one he's heavier on is the one that needs me to jiggle it and get him to flex.
He said because Duke is a thinker, I can't think inside/outside, but have to ride how he's feeling at that moment for each stride.  He said Duke won't do well if I put him in a frame and then just expect him to go around and around without changing.
We also worked a bit on transitions - John said don't pull back, and so I immediately threw the reins loose and forward.  He said that I can make an imaginary line and don't pull back just means don't pull past that line, but if Duke grabs on one side or gets tight, then that changes the game and my hands can react.  We ended up, when I thought about it all the way through, with some decent transitions.
I should video these, and then turn them into the write up.  I feel like I forget so much of what John says between the lesson and getting home.  Then again, I can only work on a few things at a time, so he introduces them, they percolate, and eventually I'm ready to work on them at home alone.  Speaking of, John said he expects I don't ask Duke to go forward enough at home, and I think that's right, I'm just satisfied with a half decent frame.
Afterwards, because mom was here and it wasn't raining, we walked down to the pond and back.  Duke was pretty nervous about this.  Then he had baby carrots, which he was ecstatic about.  I wonder if he's never had a baby carrot before.