I have mixed feelings about Save the Cat by Blake Shelton. On one hand, it takes a cynical, commercialistic approach to the art of storytelling. On the other, he has some pretty dang good points. I’ve been thinking about his story physics lately–rather, one law in particular. He says that each story is allowed one magical element.
Fantasy writers needn’t worry. Their magic is usually in the concept and is therefore weaved into every part of the story. For instance, you can flesh out a detailed magical system that exists in a medieval-esque alternate universe. Your characters can cast spell after spell, over and over, but it’s still just one magic act.
The problems arise when you try to add something on top of that. While a giant, talking turtle upon whose back the world sits might be consistent with whatever universe you’ve designed, aliens may not be. If you have UFOs floating over your wizard school, you might want to go back to the beginning and reassess.
Of course, it’s not always as obvious as that, and writing style and storytelling are often subjective; we creatives often work in shades of gray. Authors also have a tendency to miss the forest for the trees. They’re so immersed in their story, so familiar with it that they can miss huge problems.
To fix this, I recommend going back to your premise or concept. If you have an ‘and’ in there, maybe take a second to think about cutting something out. Ask your writer friends and beta readers for recommendations. And, of course, you can hire an editor, writing coach, or story doctor.