Dedicate several months to study for the GMAT. This is a difficult test which you cannot ace with a week of studying.
Take a GMAT preparation course, which will break down the material on the test. This may be optimal for those who find it hard to force themselves to sit down and study on their own. If you are unwilling to spend the money on a course, purchase a GMAT prep book. Make sure the prep book has several practice tests that are formatted in the same way as the actual GMAT, which includes a four-hour time limit.
Review the GMAT material rigorously. Allot a solid few hours each day to go over the material, which will explained within the prep book. Do not stress excessively; if you feel that you are getting overwhelmed or are tired, take a walk or stretch.
Join a GMAT forum, like www.shorechase.com. Such a forum will email you on a daily basis GMAT questions, ranging from easy to difficult, along with solutions and explanations. Joining a forum will also provide the option of asking questions and sharing experiences with others who are preparing for the test.
Get a full night's sleep before the GMAT. Try to refrain from stressing, as this may cause you to forget information when it comes to taking the GMAT.