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.
It`s important to give context that will help your reader understand your argument. This might involve providing background information, giving an overview of important academic work or debates on the topic, and explaining difficult terms. Don`t provide too much detail in the introduction—you can elaborate in the body of your essay.
Some students react to the time pressure of essay exams by scribbling down their introduction as soon as they`ve read the question and figuring out their points as they go. While it might seem counter-intuitive, taking five or ten minutes before you start writing in order to draw up a plan will be an enormous time saver.
However, it`s important to keep in mind that your professor understands the circumstances under which the essay was written. They`re fully aware of the time pressure you were dealing with, and they will judge your work far differently than they would judge a typical essay with a deadline set weeks after the assignment date.
Before you start writing, you should make sure you have a clear idea of what you want to say and how you`re going to say it.
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.