When constructing an argument, it is important that your reader be convinced not only by your personal opinion, but by factual and emotion-based data.
Choose a subject that you have a personal interest in and that you have a definite opinion on. Write a thesis that states your subject and what your position is on it. Then construct a 3-4 page argumentative paper using not only your opinion, but sufficient research material. Make sure to use APA style documentation.
Look within your community and find an issue that needs a solution, such as the need for a skate park or more drinking and driving education. Then create a 20 slide PowerPoint presentation that you would present to a community group to garner its support. Use research, a reference slide, and in-text citations.