Don't spend a lot of time reading and analyzing the passage. Read it once and don't spend a lot of time trying to understand everything. I read my passages as fast as I can mouth the words. By mouthing the words, I can infer some sense of tone. If I read the passage silently, I tend to slow down and over-analyze it as if it was a scientific paper.
Read the questions very carefully and understand them and the answer choices very thoroughly before choosing your answer.
Learn to trust your first choice. It will be correct more often than second-guessing yourself will be.