There’s only one crucial rule you need to follow when writing the end of your novel: let your characters, not the plot, determine the ending. Like it or not, this will make it feel authentic, even if it kills you, even if you had another ending in mind the whole time. Because readers know — they know when the ending fits, and they absolutely know when it doesn’t.
Even if your ending is pretty straight-forward, you can also easily work in a rewarding surprise for your readers. Here are some tips:
Twists aren’t just for thrillers! All stories are mysteries, and I don’t mean in the textbook way — Mrs. Peacock in the kitchen with the lead pipe and so on. All your favorite stories have conflict and sturdy complicated protagonists. They all have suspense and drive and push you to a finish that has at least one twist you didn’t see coming. An ending which just annihilated me as a reader is from Underworld. Even though DeLillo practically tells us the book’s going to end with that gunshot (before the more temperate epilogue), it’s still a delirious gut-punch that knocks the wind out of us, and that is one book we will never see shelved in Mystery/Thriller.
Write a couple of endings and use them both. When I started Two Girls Down, I had one ending in mind and wrote the first half of the book toward that scene. As I neared it I realized it wasn’t the end of the whole thing but that it made a great suspenseful “first ending,” splitting the story into two parts. You could do this with as many endings as you wanted, as long as you wrote a story long enough to sustain them.
Stay away from gimmicks. Don’t force a twist just to have a twist. Bruce Willis doesn’t always have to be a ghost. But this leads us to the next tip…
The twist doesn’t necessarily have to be a dramatic event. The thing doesn’t have to be big; it doesn’t even have to be a thing. It can be a guy having coffee, or it can be a guy thinking about having coffee. Of course the guy could also pour it down his pants or throw it in someone else’s face. You can contour the twist to fit the end of your story.
Let the ending surprise you. This may seem obvious, but try to keep an open mind; you don’t have to commit to an ending before you get there. I actually find this true with all parts of the story, but with endings especially because we put a lot of pressure on them. As writers we want them to wrap everything up, all the tension and emotion we’ve built throughout but still give the reader a good jump. As readers we want the unexpected, the unpredictable, but we still want it to make sense.
As readers and writers, we all want to end up different from where we started, either emotionally transformed on the farm in Kansas or holding the gun in a Bronx basement. It’s up to each of us to figure out how to get there.