Dressage workout in draw reins

We had a fabulous dressage lesson today.  At the start, John said that I am scrunching my leg up to give the aid, instead of leaving my leg long.  I'm also pushing it too far back, instead of keeping it up near the girth.
John had us start by doing 20 meter circles and then the long side, and getting Duke bent to the inside.  Duke was a little dull (!) to start, so he had me give him one good kick with the outside leg to get him to pay attention, but it only took the one kick.
Then he had us do leg yields to the wall from the quarter line.  To get Duke to step under himself, I twisted my inside toe (the one he was moving off of) towards the inside, so that I could use my spur to give him an aid.  This also made him perk up and pay attention.  I'd bend him to the inside, then open my outside rein (the one on the wall, the direction he was going) off of his neck, and then I'd use some spur, but use the outside rein to keep him from leading with his shoulders.
From there we did some canter on a circle, to canter lengthening and then back.  John had me bend him a little to the outside, and then do a little renvers (haunches also to the outside), and then he'd have me adjust my legs a bit to help bend Duke around me.  Duke did some lovely lengthening and coming back.
Then John had us do some more leg yields on the quarter line, and then we did lengthen in the trot, going across the diagonal and also down the long side.  Duke got better and better at these, but they got harder and harder for me (I felt all floppy) as we both got tired.
Poor Duke was really huffing and puffing.  It was another day where I had to wash him off afterwards.
John said that we needed to see how he did at his first show before he really started schooling me on the movements, although we've done them all in bits and pieces.  He said he didn't want me to focus so much on trying to get the same lengthening as a lesson that I overlooked just keeping Duke calm.
He said the challenge we're going to have at the show is the balance between having a calm Duke and a neurotic Duke.  For now, calm Duke is better.  But if I get in a situation again where I'm the first to go and they ring the bell and I haven't had time to warm up, he said to trot, walk a few steps, trot again.  If Duke isn't sharp, then walk again, and then trot again.  Use the whole 45 seconds if I need it to get him sharp, so that his first few movements aren't frazzled and strung out.
We also talked about the difference in feel from Charlie on cross country - Charlie was easy going but sometimes hardly looking at the fence, and Duke is locking onto the fence and ready to charge.  He said Duke's jumping style is going to be a little harder to photo (almost all of the photos of me from Spokane xc were appalling) because he hesitates then jumps.  John uses their breathing to tell pace, and he said we're not quite ready to work on pace yet, but we can later.  He also said what I need to work on is the difference in feel between Duke stretching over his back and lengthening, not just the pace (so we don't need to do the 5-6-7 on a long side exercise yet, just the feel of him pushing up and over).
He said to ride in draw reins all week, up to EI, and not to use my reluctance as an excuse to not really use them.