Commercial fiction is written to entertain, but audiences can be very picky about the type of story they want to read or watch. Most genres engage the same issues as literary and mainstream, but they engage the issues within the genre framework, disguising a familiar topic in the trappings of their genre.
To a writer, every story is unique, but words like “unique”, “good”, and “interesting” are almost meaningless by themselves. People need a frame of reference. Publishers need to know what kind of story they’re reading in order to evaluate it properly, and audiences need some way of deciding whether this is the right story for them.
If a finished draft is too long, or too short, the first step is to create a fresh outline, from scratch. This ensures the outline is accurate, and helps you to review the story as a whole. Ideally you should create multiple outlines at different scales. First, describe each scene in 1-5 sentences. Then, if the story is a novel, describe each chapter in 1-2 sentences. Last, identify the 2-5 key moments in the story.
All stories have three things in common: they begin with a status quo, use a conflict to disrupt the status quo, and end when the character either restores the previous status quo, or creates a new one. Depending on the scope of a story, the entire narrative may take place over a few minutes, or a character’s lifetime; generally larger spans of time lead to longer stories.
A good story keeps the audience focused on what’s happening, while allowing them to subconsciously recognize the underlying the patterns. As a writer it’s important to understand how and why a story works. I will often start with an idea, character, or conflict, and wait until the revision process to try and understand what pattern I’m trying to create, but that is only a preference.