Choose a category, one you know a lot about already. According to former "Jeopardy!" writer Carlo Panno, questions fall into one of six categories: Entertainment, People, Lifestyles, Trivia, Academic, Wordplay. Among those categories, questions can fall under any heading imaginable, everything from Opera to South Africa to Internet Slang. If you love to travel, you might choose Geography, which would fall under the Academic categories. We'll use this common category for an example.
Determine the answer to your first question, which should be relatively easy. In the Geography category, a good example would be "A: What is the Potomac river?" At the first level, your answer should be easy to get. Since the Potomac is a major river in the U.S. that anyone with a reasonable knowledge of geography would know, it's a good choice for the first question.
Write a statement describing the answer easily. (Example: "Q: This river flows through the District of Columbia.") Since this is the most identifying feature of this particular river, it's easy to get and thus a good choice for the first level.
Write four more questions, with the level of difficulty increasing proportionately to the dollar amount each question is worth. Each succeeding level is worth $200 more than the previous one (or in the Double Jeopardy round, $400 more). Often all it takes to turn an easy question into a difficult one is using a more obscure fact for an answer. In the above example of "A: What is the Potomac river?," instead of using the most identifying feature of the river, you might say, "Q: In 1859, the siege of Harper's Ferry took place at the confluence of this and the Susquehanna." Since this is a less well-known fact about the Potomac river, the question becomes more difficult, even though the answer is the same.
Verify your answers. According to former "Jeopardy!" clue writer Carlo Panno, each question requires verification from at least two sources before it can be used on the show. Primary sources are preferred (for example, the autobiography of a famous person or, in the above example, an atlas of Washington, D.C.). Internet sources do not qualify.