Get familiar with the nature of the test so you can focus in right direction for your studies. The computer-adaptive structure of the GMAT allows the test to change. The first question will be of moderate skill level, and if you get the answer right the next question will be more difficult. If you get the answer wrong, the next question will be less difficult.
When preparing to pass the GMAT, familiarize yourself with the structure of the questions before studying up on the subjects. Recognizing how to read and answer the questions will give you a leg up on the test.
Take a practice test that will be like the actual test itself. This will give you a good idea of what you need to focus on when studying. Get a book and go online to help get information on studying for the exam, or pay for professional tutoring.
On the day of the test, be sure to pace yourself. Give yourself more time to answer the first few questions, and then space out your remaining questions evenly in the amount of time remaining. By allowing yourself to slow down in the beginning, and acing the most important questions accurately, you will be more apt to pass the GMAT.
The week before the test, get lots of rest, take three prep tests online or in book form, and be prepared. Have your ID with you, and all of the allowed materials that you will need (pencils and paper mostly).