For me, it depends on the ride.
For most 50s, I don't do anything to Dream herself immediately after a ride other than make sure she is comfortable in terms of temperature (I may blanket at a ride whereas she is never blanketed at home) and get her as clean as possible (to remove all the sweat and trail grime). Once we are home, she will get a week to 10 days off from any riding to just relax in the pasture.
After 100s (or if its been a particularly hard 50), I do apply clay poultice to all 4 legs from the elbows/stifles down. Same care in terms of temperature and cleaning. Once we are home, she gets 2-3 weeks off to be a horse in the pasture.
No NSAIDS. No change in feed.
There is no joy equal to that found on the back of a horse.