Between Oly lifting training, Crossfit and carving, my knees hate me pretty much all the time.
Glucosamine daily, ibuprofen right after riding, rolling series on the quads/glutes/IT's, and lots of stretching in saddle pose keep knee pain in check pretty well for me. A lot of mine is compression - my knees feel much worse after a day on choppy snow v a day on good groom. I notice the same when I do a lot of lifting volume, and hit the platform hard in lifting shoes. If I do the same volume in Crossfit class on the rubber mats with softer shoes, I don't have anywhere near the same issues.
I've been thinking about knee sleeves too, it sounds like I might have to get some.