To help you prepare for the WPE, it is a good idea to write one or more practice essays. After you have written a practice essay, you can make an appointment with a tutor in the writing center to go over your essay.
When you take the actual WPE, you will have 90 minutes to write, and you will not know what the topic is ahead of time. Therefore, when you decide to write a practice essay, make sure you have 90 minutes of uninterrupted time to write, and DO NOT look at the sample topics until you are ready to begin. Also, be sure write to your essay by hand, in ink, and NOT on the computer. Doing these things will replicate the exam situation and give you a better idea of how you have done on your practice essay.
When you are ready to begin, choose one of the sample topics and get started!