If you did your best to write a complete, clear, and insightful essay within the time allotted, you should have nothing to worry about.
On the topic of planning, it`s important to sketch out an idea of how long you want to spend on each section of your essay. If you know the number of paragraphs you`ll need to write ahead of time, you can do this before the exam even starts!
Without a clear plan, you run the risk of realizing partway through that you`ve drifted off topic or written yourself into a corner, and fixing these mistakes will consume a ton of extra time.
Do your research: Read primary and secondary sources and take notes to help you work out your position and angle on the topic. You`ll use these as evidence for your points.
Become familiar with the course content. If the professor hasn`t told you in advance what a timed essay prompt will be, it can be intimidating to think that you will have to write about a subject you`ve never seen before.
You should formulate your thesis statement—the central argument you`re going to make. The thesis statement provides focus and signals your position on the topic. It is usually one or two sentences long.