Steps

1. Start studying well before the exam. Make sure your schedule provides for sufficient revision time. As any good test-taker will tell you, the revisions are more important than the first time study.
2. Focus on understanding the concepts rather than mugging. Use mnemonics if rote learning is the only way out.
3. Think about the time after the exam. Visualize the happiness on your face that the stress period is now over. This thing works very well.
4. Keep telling yourself that your hard-work will not go to waste.
5. If you are afraid of tough questions, it helps to know that most questions are of average difficulty and designed to be answered correctly by most examinees.
6. Designate a "study buddy", a classmate who is an expert in a subject you have trouble in, that you can come to with questions.
7. Get plenty of sleep. It's way more stressful to memorize lots of information or comprehend complicated concepts on less than 6 hours sleep.
8. Eat healthy food, since it's often easier to function on nutritious food than junk. While sugar might be a quick source of energy, sugar lows happen pretty fast and the let-down can often be severe.
9. While taking notes, use as many diagrams, graphs and figures and illustrations as possible. This helps to make several revisions at the last moment!
10. Ask a senior or more knowledgeable person to prepare sample tests for you. If such practise tests are available in the market, go for them. Many questions are similar to or verbatim from practise material.
11. On the day of the exam, feel happy! Think positive and keep cool! Good luck!