Choose a topic that is difficult or controversial to explain. Some good topics include hoaxes, unusual sightings (e.g. UFOs, bigfoot, etc.), the supernatural or paranormal (ghosts, levitation, etc.), conspiracy theories, unsolved crimes, court cases, etc.
Reflect: Do a little research to find a specific topic and learn about explanations on both sides. Consider what you think might best explain the observed facts of the case.
Write: Explain the topic you chose and why it is interesting or controversial. Present good arguments on more than one side of the issue (e.g. competing explanations of the facts). Analyze both arguments that you have presented. Then present your own argument for your theory that you feel will best explain this phenomenon. Are there any holes in your theory? Is there any information that would be likely to strengthen or weaken your case?