The best preparation going in is what you’ve been learning your entire life. Anything extra might raise your grade a few hundred points, but don’t stress about it. About my score: I’m generally good at standardized tests. My Math score wasn’t great when I first started. I memorized the formulas before the test, got it up to 660, and decided to stop there. (This was probably influenced by the fact that I took it at the latest possible date, though.)
You’ll most likely improve on the next test because you’re familiar with it. So be optimistic about that. Buy an SAT practice book and just work through it. It’s the “authority” and will give you better advice than anyone who just took the test.
Also: In general, steer away from comparing yourself to others. It’s so much better when you don’t!