Unless if you finished way ahead of schedule, don`t worry about major revisions like reorganizing the structure of the essay–it`s better to hand in an essay with an imperfect structure than a paper that`s impossible to follow because you had to stop halfway through the revision process.
Although the conclusion paragraph comes at the end of your essay it should not be seen as an afterthought. As the final paragraph is represents your last chance to make your case and, as such, should follow an extremely rigid format.
Create an outline: Map out the rough structure of your essay in an outline. This makes it easier to start writing and keeps you on track as you go.
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.
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.
Start planning if you can. Although the situation described above sometimes occurs, it`s also very common for professors to give their students a fairly detailed idea of what an essay question will involve in advance of the test day.