I know what you mean..what I do to help with that for everything I film is create a "storyboard" or at least jot down what I want, so I'll think about what features are up at the parks and then think about what time of day the sun is shining on the skier and then I'll think about the shots I want, and other other factors. Having something written down helps remind me what I came out to get.
I only have a tripod and not a Glidecam, which makes it harder for me to just get out and film, but it forces me to focus on angles and such since I have to spend some time setting it up.
One thing I would do also (I just thought about this) is follow your skier on the same lap twice. Have them try to hit the same tricks on each feature, and film them on opposite sides. This will give you to angles on every trick (or every trick they don't mess up haha), and you can put them together when you edit and that gives you a two camera view/effect. Just make sure you do the laps back to back or you'll end up with awkward lighting changes.
Hope all this helps.
