Read every sentence in the stimulus material. It's true you're sometimes given irrelevant material, but don't dismiss it until you've actually assessed it in terms of what you've been asked. Work with the test, not against it. Use the Four Important Points to Remember listed above. All problems have been thoroughly tested.
Every word is there on purpose.
Keep track of time but don't be possessed by it. Resist pressure by working at the faster pace than is productive for you. Many people don't finish. The score comes from getting questions right, not just from getting them answered, and a correct guess is as good as a right answer, whether you like it or not. Don't waver about guessing.