Start by writing the points of the essay on a paper.
Make an interesting introduction. It shouldn't be too long. Short, simple, and interesting.
Start writing the paragraphs. If you can, insert a little humour, or make a complex sentence (recommended).
Conclude the whole paragraph.
And then proofread. Don't write a long essay.
An essay is not suppose to be long to be enjoyable. The longer the essay, the more mistake you might make while writing. Keep it at medium-at-most length.
Hope I helped.