Sentence Completion (aka the Vocab Questions):
Ok, here's "The Method": Any time you don't know a word, look it up. Period. End of story. Even if you got the question right.** Then, use these words often, even at the risk of using them incorrectly (see The Essential Mistake). I'm a big fan of Wordnick (puts them in context); I'm also a believer in homemade flashcards.
When you're taking the SAT, read the sentence, then jot down the first words that come to mind (even if they're not "the big fancy vocab words"). Pick the word you feel most strongly about (if there are two blanks), and see which one (or two) works in the answer choices.
CROSS OUT WRONG ANSWERS -- as in, put a line through them and get them out of your line of vision. You'll most likely be down to two answers by this point. Then, look at the second word you jotted down and see which of the two answers left works. This is as much about the process of elimination as is about knowing the definitions of the words.
Oh, and one more thing: Beware of the backwards words (i.e. those words that make the answer the opposite of what you're thinking -- words such as "however" or "but," etc.).
**Okay, I know you're not going to really do this (I have two teenagers, don't forget). But, even if you do this 75% of the time -- ok, even 60% of the time.....you will do significantly better.
Illustrations by Jennifer Orkin Lewis