While it is important for you to have a strong interest in a topic, about.com explains that an argumentative essay requires more than that. You have to think about your point of view and back it up with sound reasoning. The ultimate goal of your essay is to convey a logical and clear argument. Remember, a good argument is not one-sided, so you should also think about counter-arguments.
A good paper must start with a clear introduction. As supremeessays.com states, argumentative essays need a proposition, a claim that's open to argument. You want to begin with a supported statement that is not based on a general fact or opinion. Typically, this will comprise of three to four statements. Your introduction should set the stage for what your reader can expect throughout the remainder of your paper.
After you introduce your arguments, explore them thoughtfully. Helium.com recommends you do this point by point, supporting each point with a referenced quote or example. In your conclusion, you want to provide an overview of what was said in your paper but you should try not to simply restate all that you've said. Leave your reader with something to think about.