Work on angles more than anything. Whenever I self film, I spend at least 5 minutes testing different angles. There was one grind clip I filmed 14 times for my edit to find the best angle. Oh, and don't get too close - it will blur and look really sketchy.
With angles:
Stay out of bright light
Give a wide enough angle that you don't run off screen
Stay low and point high rather than the other way round
Always ride facing the camera, or if it's a fakie trick then start the other way
My edit is mainly self filmed, I know it's not great, but it might help start you off