So how do you know when to make your ending a twist? How do you find the end to your novel? I've taken some classes that discuss this at length. One good article you can find online: How to Write the End of a Novel by C. Patrick Schulze. He presents the basic types of endings as well as some tips for how to write the end of a novel. One of my favorites:
Ensure your ending delivers as much emotion as did the beginning and middle.And something I'm trying to do in my work in progress:
Draw it naturally from your characters’ personalities.Also in this article? The four unacceptable endings. I'm sure none of you have ever used one of these.