I like to play on Medium. It allows me to get every medal/rank, gives me a good fight (I suck horribly. 'Medium' is challenging for me), and gives me the satisfaction of knowing that I'm playing at a decent level.
All I can say at that level is never stop moving, dodge a lot, and for some reason, if you spin while in a direct straight course (Especially toward capital ships/installations), shots are more likely to miss you. I don't know why, but it's helped me often on bombing runs.
Other than that, you're crazy for wanting to play at a higher level than medium...