Replying to Help me out

Ok so basically I am VERY inflexible (like with my knees straight i can only get half way down my shins, MAYBE 2/3) and its starting to affect my skiing because doing grabs is alot harder. Since the season is over i'm looking for exercises to do to get more flexible so i can ski better. if it matters i'm still young (14) and i am definitely growing. anything you guys could recommend that you might have done? does just strecthing at night and doing the whole reach as far as you can, count to 10, reach a little bit farther, count to ten, etc even work?