Over the last two years, I've lost close to 50 pounds, which has helped enormously but I should probably lose another 5 or 10. I try to do some walk-run stuff every week, along with my usual walking routine.
At the suggestion of a clinician, I try to do stretching/warmup exercises in the saddle while we're doing our walk warmup.
I also took the same clinician's advice to the letter and did all his homework religiously this summer. I signed up for two sessions with him, and I got a lot more out of it. I'll do the same this fall.
Since my current horse is green (but well behaved), long-backed and big-strided and a bit gangly, I spent a lot of time perfecting all the basics for showing this summer: halts, good circles, good turns down the centreline, accuracy, etc. That really paid off in our scores and I feel I can set it aside for a while and work on more general training objectives.
I made a vow to do 10 minutes of no-stirrup work at least twice a week this winter.
Otherwise, just being focussed and sticking to our schooling objectives--we're working towards more engagement. I have a list of things I'm working on and I do them every schooling ride. My trainer has already noticed a difference.
What I'm doing for myself is like the others losing weight, becoming fitter and increasing my knowledge. Through SITS(success In the saddle), pilates, walking, swimming and bike riding. Doing many different types of exercise keeps it fresh for me. I also have purchased and studied many DVDs/books. Not watched 1 time but studied and returned again and again to them. My favorites are Walter Zettl and Jane Savioe but I have many others. I also ride without stirrups regularly almost everyday and check check my position via Jane Savioe's 'Program your position'. I was lunged regularly without reins and stirrups on my horse regularly in my past.
What I do for my horse is make sure she is as fit as possible as well and do exercises to strengthen her but keep it fresh too. I do carrot stretches and other things on the ground to strengthen her back to make her work easier. If she is happy in her work I can be happy too.