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.
For this reason, it can be helpful to simulate the conditions of a timed exam before the actual day: pick a practice question, find some lined paper, set a stopwatch, and see how you do!
Take note of the amount of time allotted for the exam and split it into reasonably-sized segments, leaving some time at the end for revision if possible. Without a schedule to follow, it`s easy to become too focused on a single paragraph and run out of time to finish the essay.
The introduction sets the tone for your essay. It should grab the reader`s interest and inform them of what to expect. The introduction generally comprises 10–20% of the text.
Decide on your thesis, the topic of each paragraph, and the arguments which you intend to cover, then jot down some quick point-form notes. This process won`t take long, and, once you complete it, all that`s left will be to expand those notes into a well-organized essay.