Kaplan's Five Basic Principles of Test Expertise
Feel Free to Skip Around
One of the most valuable strategies to help you finish the sections in time is to learn to recognize and deal first with the questions that are easier and more familiar to you. That means temporarily skipping those that promise to be difficult and time-consuming, if you feel comfortable doing so. You can always come back to these at the end, and if you run out of time, you're much better off not getting to questions you may have had difficulty with, rather than missing out on potentially score-raising material. Of course, since there's no guessing penalty, always fill in an answer to every question on the test, whether you get to it or not.
This strategy is difficult for most test takers; we're conditioned to do things in order. But give it a try when you practice. Remember, if you do the test in the exact order given, you're letting the test makers control you. But you control how you take this test. On the other hand, if skipping around goes against your moral fiber and makes you a nervous wreck, don't do it. Just be mindful of the clock, and don't get bogged down with the tough questions.