Start with a broad topic. For example, let us assume you want to write a novel about discrimination. There are many groups that have faced discrimination, and the topic has a very long history.
Start narrowing the topic by selecting a specific group of people. In the above example, pick a specific group of people who have faced or are facing discrimination. An example would be Asians, who have been discriminated against in different parts of the world for centuries.
Decide on the demographic. You can write about adults, children, teenagers or a combination of all three. While the cast of characters should include people from all ages, the age of your main character or characters will dictate the demographic of the story. In our example, we can pick teenagers.
Select a specific location. Using our example, we can focus on discrimination against Asians in America. You can get even more specific by defining a particular region of America, such as New York City. This way, you can work with a smaller cast of characters, allowing the reader to really get to know each one.
Define your time period. This can be as narrow as a day or two, or as broad as a lifetime. Keep in mind that the longer the time line is, the more difficult it will be to write an in-depth story. Continuing with our example, we can write about discrimination against Asian Americans in New York City during World War II.
Research as much as possible the topics involved with your story. In our example of a story about discrimination faced by a teenage Asian American in New York City during World War II, you should research what it was like to be a teenager in that time period and in that location, as well as cultural differences between Asian upbringing and traditional American upbringing.