Be prepared emotionally and physically as well as intellectually. Stay away from others right before the test.
Anxiety is highly contagious.
Get your rest the night before a test, eat well balanced meals, keep up with your regular exercise - prepare your brain for optimum functioning by keeping your physical resources well maintained. Arrive at the test room early enough to arrange your working conditions, establishing a calm and alert mode. When you receive your test, use the back to jot down all the information you are worried you might forget. Remember first to ask whether you can write on the test form itself. Preview the whole test before beginning to answer any questions.