Outlining a Novel
There are a variety of ways to write a novel, and one integral step is to outline the story. Outlines can be as broad or specific as the writer desires. For example, the first novel in my Fanzam series had a sparse outline, detailing major plot points only. Everything in-between was based on free-writing, meaning I had no idea where the story would go until I sat down and actually wrote it. In this way, the book "wrote itself."
Unlike the first novel, the second book in my Fanzam trilogy has an in-depth outline, where major plot points are broken down into sub-plots. For instance, one of my major plot points is: Protagonist views antagonist's memories of the past. This is an important turning point in the book, both for the reader's perception of the characters and for the protagonist's volatile reaction to these memories. Sub-plot points include the antagonist's individual memories and what they entail, such as: previously unknown relationships, gang rivalries, military interventions, trans-dimensional loan sharks and parallel dimensions, and ultimately several deaths.
There are benefits and drawbacks to both broad outlines and highly detailed outlines. The most obvious drawbacks being the potential for a less focused story/wandering narrative in a broad outline, versus a rigid/unnatural flow in an overly detailed outline. However, there is no right or wrong way to develop a story, and each book will likely require a different approach based on the content itself as well as the skills/experience of the writer.