Check first whether you can formulate a statement that can be argued. An acceptable argument should convince or persuade readers to do something, change their minds about an issue, address a question or problem for which there are multiple solutions or expect that readers may have conflicting opinions about the topic.
Learn the "classical" form of argumentative writing -- so-called because it follows a pattern recommended by ancient rhetoricians. To practice, try writing a classical but "low-pressure" argument, such as why your curfew should be extended from 11 p.m. to midnight or why Dad should loan you the keys to his prized Lexus.
Frame your argument within the five components of the classic argument: the introduction, presentation of your position, summary of opposing views, response to opposing views and the conclusion.
Engage the reader with a compelling introduction by writing a strong thesis statement -- or a statement that succinctly defines the purpose of the argument and sets its direction.
Present your position with authority. Provide background information and plausible, credible support for the thesis. This is the heart and soul of an argumentative paper. While striving for "the voice of reason," the tone here can be moderately emotional -- hence the term and need for "emotional appeals" in argumentative writing. This is where you should appeal to a reader's feelings: compassion, empathy, sympathy or even outrage, depending on the topic.
Summarize opposing views. This is a key distinguishing aspect of argumentative writing, and it requires an honest sense of fairness and completeness. This section should size up the advantages and disadvantages of the opposing views without exaggeration or hyperbole. Strive for a tone of diplomacy and understanding without being solicitous.
Respond to opposing views. This requires the same degree of diplomacy as you refute or concede the points -- and maybe a combination of the two. Ultimately, this section should expose weaknesses in the opposing views and culminate in a strong "vote" for the thesis.
Conclude the argument. The conclusion is always the trickiest part of writing. An effective conclusion should bring the paper to an end by summarizing the argument or elaborating on the implication of the thesis, leaving the reader with a lasting impression and a heartfelt call to action.