Merely reading the questions and possible answers will stimulate your thinking. Sometimes the ideas in the questions will get you thinking about other parts of the exams. You may even find hints in one question that will help you answer other questions. READ the whole question AND answers carefully. Make sure you know what the question wants you to do.
Time is sometimes short during exams.
Longer exams require some time management. Next, work on the questions that you can answer with a little thought. Save the really tough ones for later. Erase the mark when done. Lastly work on the questions that are left.