What makes an essay perfect?

The perfect essay must have a perfect conclusion!
Conclude by linking the last paragraph to the first, perhaps by reiterating a word or phrase you used at the beginning.

Conclude with a sentence composed mainly of one-syllable words. Simple language can help create an effect of understated drama.

Conclude with a sentence that’s compound or parallel in structure; such sentences can establish a sense of balance or order that may feel just right at the end of a complex discussion.

And here’s how you should never end an essay:

Don’t simply summarize your essay. A brief summary of your argument may be useful, especially if your essay is long_more than ten pages or so. But shorter essays tend not to require a restatement of your main ideas.

Avoid phrases like “in conclusion,” “to conclude,” “in summary,” and “to sum up.” These phrases can be useful_even welcome_in oral presentations. But readers can see, by the tell-tale compression of the pages, when an essay is about to end. You’ll irritate your audience if you belabor the obvious.