Start at the beginning. The SAT has easier questions at the beginning of each section. As you near the end of a section, the questions increase in difficulty.
Monitor your time. Limit the amount of time you allow yourself to answer a particular question or a specific group of questions in a section. You may want to mark these questions and come back to them if time permits.
Pass over the questions you can't answer. More points are deducted from your SAT score if you guess incorrectly at an answer than if it is simply left blank. You gain nothing by making a random choice.
Make an educated guess. If there is the possibility of you eliminating one or more of the choices, then it's advised to take a guess. Definitively ruling out an answer or two greatly improves your chances of answering the SAT question correctly.
Prepare for the SAT. Studying for the SAT can only improve your score. Taking practice tests and investing in study guides will familiarize you with past SAT questions and the format of the exam. When studying, put most of your effort into subjects that give you the most trouble.
Get a good night's sleep the night before the SAT. While preparing for the SAT is important, so is getting enough rest. Taking the exam with a well-rested mind can make all the difference when answering questions.