R.I.C.E. rest ice compress elevate, look that up on google if you have no idea what i'm talking about, icing seems to be best, do it 2 - 3 times daily and rest them if you can, my knees suck goat balls but i'm fortunate and haven't torn anything so i'm doing all i can to prevent crap from happening, like stretching and strengthening consistently, if your knees are hurting find out whatever you can like on the net or in books and see if you can figure out what the problem is, one thing i heard is that simply leaning back in your ski boots can put tons of stress on them and eventually F them up, so maybe change up your technique and see if it helps, good luck dude