Take 3-4 practice Critical Reading Sections. Make sure to look at why you missed the questions you did.
Make flashcards for the vocab in Ned and TED's "In A Word" (see the lyrics with embedded definitions here)
Keep studying all your math and vocab flashcards.
Take at least one full, timed practice test.
The Official SAT Study Guide (Paperback)
This is the only book with practice tests that are actually written by the creators of the SAT. In other books, we have come across occasional mistakes and the questions aren't quite the same as the real test. Without a doubt, these are the most realistic practice tests available.