A successful persuasive essay starts with intensive research on your topic. It is imperative that the essay include facts from experts to support your opinion. You should be well-read on the subject matter and include a variety of sources from magazine articles, web-based references, newspapers and books.
It is equally important to research the opposite point of view. There is more than one opinion to be formed in persuasive writing, so being well-versed in the opposite perspective will help you build counter arguments against it.
Convey your point using a variety of avenues---stated as your opinion, an example or a quote from an expert on the subject---and summarized in your essay's conclusion. Repetition helps your readers fully understand what you're saying, making it easier to agree with you.
Use metaphors and analogies to make your case. This ties your opinion to something the reader already accepts to be true, which proves more persuasive.