Eliminate distractions. Turn off your cellphone, and tell your buddy to stop passing you notes. Not only will sending text messages and talking take up your time, you probably will get into more trouble if you are caught.
Gather everything you need to write the essay. Because you probably won't have access to a computer, get out plenty of paper. Find out whether the proctor prefers ink or pencil, and use the correct utensil. Failure to do so may mean another detention or a rewrite. If the essay is on a specific topic, ensure you have research books you may need.
Know the directions. Most likely, the essay you write in detention has an assigned prompt, page length and audience, which probably is the teacher overseeing detention. You also have a time limit. This information will influence how you plan, and it will shape and inform the essay's flow, structure and content. Charging into an essay without paying careful attention to instructions only leads to wasted time and could lead to a longer detention.
Select a subject and angle. Even if the essay has an assigned question, you can find an innovative way to attack the essay. If the topic is up to you, write about something that fascinates you. Don't write about anything antagonistic, such as "why I hate school."
Write a thesis statement. This is the crux of your essay and informs all other information. A good thesis statement clearly states what you will prove in the essay. For example, if the essay prompt is "the best kind of jelly bean," your thesis could be: "Red jelly beans are the best because strawberry packs the most flavor."
Plan the rest of the essay. In detention, you probably won't have access to many research materials beyond the books you brought, but you still have access to your mind. Think of facts or opinions that will support the thesis. Then, on a piece of scrap paper, sketch out a quick outline of your main points. Ensure each point connects to the argument of your thesis statement. Information that doesn't further your argument distracts and muddles it. Because you have limited time, write down how much time you want to spend on each point. Divide your time wisely and honestly; don't spend more than half of your time on one point and then rush through the other points. Give yourself several minutes to revise and proofread the essay.
Write a quick introduction. Spend a few lines, but not more than four or five sentences, discussing your prompt or topic. This allows the reader to "get into" your subject. The introduction should be brief because your detention proctor probably really wants to get quickly into the real "meat" of your argument. Filling up your introduction with flourishes and detours only wastes your time. End the introduction with the thesis statement.
Write the body of the essay using your outline. Depending on the prompt, you should have about three points you wish to make. For each point, write a paragraph (four to six sentences) discussing the point and how it relates to your argument. Keep to your timetable and outline. These tools will help you stay on track.
Write a conclusion. In a short paragraph, wrap up your argument and reiterate your thesis. Don't summarize the entire essay, but neatly tie together your most important points.
Revise the essay. This may seem like a waste of time, but turning in a poor or rushed essay could mean more time spent in detention. Revision is the key to good writing. Read your writing. Check your argument, and remove everything extraneous. Don't pad your essay with useless information or words just to reach a certain length. This comes across to the reader very clearly and could mean a rewrite. Try to make your essay as concise, clear and logical as possible.
Read the essay once more. Ensure every word is spelled correctly and the essay follows grammar and style rules. Because the teacher leading detention is probably a stickler for technicality, your essay should be flawless.