I believe that timing is one of the most important aspects of exams. For me giving yourself strict structures to your timing during exams is essential to getting the best answer. Figure out how much time you have per question and then structure from there. You want to give yourself at least 5 minutes for planning your answer and creating an idea. Then the body of the answer will take the most time, but you want to make sure you have 5 minutes at the end to re read over your answer and correct any mistakes. Strictly keeping to these times and making sure you don't run over is one of the best ways to tackle hour long exams and not get too stressed.