Keeping your mind and body relaxed before an exam is the most important thing. Look after your health and sleep properly so that your mind stays fresh. This way, you will pick up things better than normal.
Exam time is a time when you should cut yourself off from the normal routine. There should be no gaming, television, movies, texting etc. You will just have to make this sacrifice for a couple of weeks, but it will be worth it eventually.
Gather all the necessary information
It is important to collect all the necessary data related to your subject and focus on the important notes. You need to work smart rather than hard. Do not waste time in things you know will not be asked in the paper.
Whenever you are confused over something, don’t hesitate asking your teachers or close friends about it.
Lay down a plan for how you will attempt the paper
Preparing for the paper is one things but executing it in the test hall is entirely another. You should have a plan for attempting the paper. The various sections need to be timed, so that you are not pushed for time at the end.