First of all, read the whole sentence on SAT Reading Section to get an overall picture of the sentence. Getting the sense of the meaning reflected by the sentence gives clues for the words that can be fit in the blanks. If you read only a part of the sentence, part before the blank or after the blank, and try to arrive at the correct answer choice, you are moving in wrong direction. You should read the sentence in such a way that when you end reading the sentence, you must know what you have read. Remember, you have to read an incomplete sentence to get a big picture. Once you succeed in getting the sense of the sentence, your chances to choose wrong choice are diminished.