I do a lot of hill work and gallop sets on the conditioning trails, Jessica. I really like it, but I have some “playful” OTTBs that would rather be silly than do fitness, so they need ring work. Totally agree on hillwork though.
I incorporate Cavaletti work into every ride to work on footwork, hind end strength, and gaits. I use spiraling in/out on a 20M circle for some horses that need it, but not always do I use it. Totally good ideas though, Emilia!