Many writing teachers will tell students an essay falls into three basic parts that can be expressed with the statement, "Say what you're going to say; say it; then say what you said." The first part of the essay is therefore the opening paragraph in which the writer introduces a topic and writes a thesis statement. The next part is the supporting paragraphs in which the writer proves his or her points. The final part is the essay conclusion, in which the writer clearly and briefly summarizes what the essay has been about.
The essay conclusion should not, however, be a re-statement of the thesis word for word. It should, instead, give the reader an easy summation to remember or reflect upon so when they finish reading the essay, they walk away still thinking about the topic and the arguments presented. The best way to write an essay conclusion is to first make a brief outline of the entire paper. This outline should include the thesis statement and a list of the supporting points covered in the paper. This will help the writer keep track of the main ideas that need to be summarized in the essay conclusion.
Never start the essay conclusion with the statement, "In conclusion..." The conclusion should be written well enough that a reader recognizes it as the essay conclusion, therefore making that qualifying statement superfluous. The conclusion, like all other paragraphs in the essay, should transition naturally from the previous paragraph, and the reader should not need a prompt telling them the conclusion has begun. Read the opening paragraph before writing the conclusion to help determine how the essay can be tied up logically.
Avoid asking questions of the reader in the conclusion of the essay. All the questions the writer has presented should be answered by the last paragraph. The writer should think about what he or she wants the reader to continue contemplating after the last word has been written, so the conclusion should focus on the main point of the essay and present it in such a way that the reader will remember the topic and the writer's arguments well after the essay is finished.
It can be difficult to write an essay conclusion, so the best way to get started is to simply start writing. Do not worry about the quality of he conclusion while writing the first draft; the writer can re-write and revise in subsequent drafts. Do not get hung up on grammatical concerns, spelling, and punctuation in the first draft. All of these things can be fixed later on. Just get the ideas on paper and work from there.
If you are looking for more specific advice based on your writing style, strongly consider hiring an online writing tutor.