Familiarize yourself with the format of the GMAT test by visiting the Graduate Management Admission Test website. (See Reference 1). Know and understand the three main sections of the test and the allotted time for each.
Download several GMAT preparatory exams to get a full understanding of how the computerized test works. Order paper tests from the GMAT site to use for extra practice. Start studying weeks before the test date by taking practice tests simulating the testing environment with no interruptions, no music, no eating and no phone calling. Use a timer and practice pacing yourself to complete each section. Concentrate on your weakest areas when taking the practice tests.
Do not skip questions or make random guesses in answering the questions, even if you are starting to run out of time. As you take the practice tests, learn how to make "educated" guesses by eliminating two or three wrong answers. You can increase your odds of answering correctly by eliminating even just one answer.
Read and answer the first few questions carefully. The way the GMAT computer-based test works is that it determines the difficulty range of the questions you will get by how you answer the first five questions. Difficult questions are weighted heavier in the scoring system, so paying extra attention to the first few questions will make a big difference in your section score.
Organize your thoughts first before writing in the analytical writing section. Be specific when writing, and use transitional phrases, such as "for example," to make the writing easier to follow for the reader. Provide examples, if possible. Using big words is not necessary, but good grammar is a must.
Use scratch paper during the problem-solving section. Learn how to "guesstimate" and try not to get bogged down in long calculations when trying to solve problems. For example, if you know an answer is roughly 50 percent and your answer choices are 5 percent, 13 percent, 25 percent, 49 percent and 61 percent, then you can save time by choosing 49 percent. Try to eliminate one or two obviously wrong answers if you have to make a guess.
Make a trip to the testing center prior to the day of your test to get familiar with the route and how long it will take to get there. Get a good night's sleep the night before the test. Arrive early at the testing center and become familiar with the environment.