How to Revision Your Book

I'm writing a monster book at the moment. It's called Catacomb. I've played around with world building aspects as well. Tolkien took decades to create all the languages and everything of Middle Earth. You can just ask Chappeti to make all this stuff up or to give you five or 10 examples. And then you pick the one you really liked. So given that you are an editor, how do you expect people's books to change? I think revision might become easier.