To most this should sound obvious, but the first thing to do is to read the entire question. Make sure that you grasp the question being asked.
Highlight The Important
Words in a sentence can be put in a different sequence to yield an entirely different question. The key here is to highlight with your pen or pencil the key question in the problem, what the unknown variable is and if applicable, how you are asked to solve it. In case you need to move on to the next question, having highlighted the important things will facilitate your task when you get back to it (if you have time).
Once you are ready to get cracking, remain patient and visualize your response. Rambling on aimlessly will only frustrate the grader. Take a couple of minutes to break up your essay into a simple, powerful and concise outline that will be easy to develop. Add specific chapters, company examples and class lecture references as you write the outline. It may be the single best investment in your exam.
Once you start to put down your ideas on paper, do not get cute. Get the job done, but work smart.
Wishful thinking perhaps, but it is always important to reread your answer.