Please

[smeag]

At least give me a way to prepare myself to obtain scores of 200+

[nsguy1350]

Take tests, and ask everything you cannot figure out on your own. Before you do that though, you're going to need to do some research. Learn these topics:
Mathematicians (there is a list, I think there is one on the UIL website)
Probability - learn combinations, permutations, etc.
Learn your geometry formulas for all the basic shapes
Learn about conic sections thoroughly
Integrals, derivatives, tangent lines with derivatives, area under curves, antiderivatives, evaluting definite integrals by hand (you have to get FAST at this.)
Matrices, matrix topics
All of your Algebra II topics, along with Algebra I. Logarithms, matrices, asymptotes, etc.
Learn as much as you can about trigonometry, it's relationships to triangles, and it's topics outside of geometry.
Types of numbers (evil, happy, odious, extravagant, etc.)

That's a lot to digest, and it will take a while for you to learn all that. Take it one topic at a time, and gradually, you'll see your score improving as you take tests. Learn, take a test everyday (if you can find the time, I actually take more if I can.) Make sure to ask questions! Get a group of questions and ask them at one time.