The CollegeBoard lists in it's Blue Book certain things about "doing your best." I find it humorous yet somewhat true, when they say, "You've actually been preparing for the SAT all your academic life." I guess you don't need to study much more then, right?

CollegeBoard's “Things to do to improve”

1. Learn to read effectively
2. Improve your vocabulary
3. Develop your problem-solving abilities
4. Strengthening your writing

Anish: These abstract ideals basically tell you nothing.  Ideally, in your spare time you should read some books of some importance, i.e. the classics.  That should help take care of three of the above.

Sushil:  I learned to write from reading books, classics mainly.  I learned reading comprehension from reading books, classics mainly.  I learned most of my vocabulary through reading books, classics mainly.  3 out of 4 is really quite good.  Read books, classics mainly.

Anish: I really believe that there is a correlation with how much you have read and how "naturally" talented you are at standardized tests. Voracious readers have already built up their reading comprehension and know what good writing looks and sounds like. The students I have who really struggle with the SAT always dislike reading.

Bottom line: To improve your score, it is all up to you.  All of it. 
There are no books (or websites), no tricks, no strategies, no reference materials, no teachers, no courses which will magically improve your score or drastically provide shortcuts. You may have the test prep books, but you’ve gotta use them.  You may learn the strategies, but you have to use them.  None of these strategies are tricks.  There is no guaranteed way or shortcut to get a question correct all the time except to actually do it.  You’ll always have to think, and there is no way for any other resource to MAKE or teach you to do that.  Your score is in your hands.

Don’t worry though…the SAT isn’t extraordinarily scary and earlier you realize that, the earlier you'll be ready to slaughter it.

Get your weaponry ready - we're going into battle - SAT Armamentarium