Sally Swift's Centered Riding - two tips

I watched the first DVD on Centered Riding (I loved the book years ago when I first read it), and it had two pertinent tips for me right now.
First, Sally explains the human skeleton, and shows how when you roll onto to the front of your pelvis (by rounding your lower back - sticking your stomach out in front of you and rounding your shoulders), how you "scrape" the horse instead of letting your hips absorb the motion. It was really excellent to watch the skeleton to see what your body is doing.
Second, keeping your hands steady at the trot. Because in the trot you move up and down while the horse stays still, that is when your hands move up and down with you. What she suggested is that a person stand on the ground and you hold their finger with your reins. Then you rise and feel the difference between pulling their finger up with you or leaving your hands steady on the finger. When you leave them steady, the motion is in your elbow. But it is an up and down motion, not a chicken wing motion. It's the same idea as looping a finger around the front of the saddle (like the saddle pad straps), so that you can hold them down and feel how they feel still.
Mercury got his feet done today (finally!) and I learned a lot about shoeing and abscesses from the farrier. He is going to be turned out again starting this week, so he'll be a happy horse, and then next week I'll start riding him again. I'm thinking about leasing him instead of selling him once I've got him working again.
Willig was terrible yesterday, but really good on Saturday. I feel like we're making some progress, but it's a long road ahead and it's kind of scary to face it without a trainer.