Determine what specific topic you want to write about. For example, a topic could be whether capital punishment should be legal in a certain state or country as a strategy for crime prevention, according to Docstoc.com. Once you've selected a theme for your essay on a debatable topic, begin the research process. Look through books, journals and credible websites for information relevant to your topic. You also can conduct interviews with professionals or experts in the area you are researching. Then, determine what position you want to take.
Begin writing the rough draft of your supported opinion essay. Your first paragraph should be your introduction. Explain what the topic is about and who it involves, and include the other three of the five "W's"---when, where and why---in your paragraph. Also, write a statement that catches readers' attention and makes them think about the topic. For example, include a brief anecdote, a startling statistic, a stage-setting scenario, a quote or a question. Avoid writing in first person so that the essay will be more authoritative.
Explain why you are supporting an issue in a certain way. Include at least three convincing reasons or arguments in the body of your essay, and provide supporting details based on the research you gathered. Make your strongest reason the last one you explain, and make your second-best argument the first one you introduce in your supported opinion essay. This is helpful because readers usually remember the first and last issues they read. Make sure you also mention the opposing position for your argument to ensure the essay is balanced, and strongly emphasize why this opposing position is incorrect.
End the supported opinion essay with a brief conclusion that recaps what you wrote earlier. Use this portion of the essay to join or weave any loose information together. This paragraph should reflect your introduction and offer a strong voice that once again aims to convince your readers of the point you want them to understand. If you presented a plan in your introduction, use the conclusion paragraph to rephrase it and explain what would occur if your readers followed your recommended plan.
Read over your essay and check for errors in grammar, punctuation and spelling. Also, include a bibliography section that lists the resources you used to support the information in your essay. Use the Modern Language Association (MLA) format or a format required by your instructor to help reference your claims correctly and easily.