Spend time practicing and studying as early and as much as you can. Setting aside a certain time each day is best.
Force yourself to spend small increments of time studying every day for at least one week fore the exam.
Take advantage of all pretest material you teacher makes available. They know what they are going to test you on and should be giving you information to use accordingly.
Attend any available review sessions even if you feel you don't really need it.
Plan your week before the exam to be sure you have plenty of time to study. Take time off of work the few days before your exam to allow extra time to study.
Sleep well the night before the exam and get a full eight hours.
Eat a good healthy breakfast the morning of your exam. This will help you wake up and get your brain moving.
Cram as much as possible the day of your exam to solidify any final ideas.
Ask your teacher to clear any uncertainties you have before the exam.
Do your best on the exam and do not put too much undue pressure on yourself to perform. You worked hard to get this far and can only do your best.