"Let us swear while we may, for in Heaven it will not be allowed."
Let's face it, writing a "how to" book is a lot of work. It involves a lot of time, and a lot of effort. With an investment like that, you need to get the most of it. So what's the alternative if you have already decided you need a book?
Fiction writing is any kind of writing that is not factual. Fictional writing most often takes the form of a story meant to convey an author's point of view or simply to entertain. The result of this may be a short story, novel, novella, screenplay, or drama, which are all types (though not the only types) of fictional writing styles.