☐ Epilogue, if used, is necessary and engaging.
It’s not enough that your epilogue be sweet and show how your characters live happily ever after. It has to wrap up the story in a way that, if it were omitted, the reader would feel some loose end was left hanging.
Generally speaking, most of your loose ends will be tied up either right before the climax or during it. Whatever’s left is tied up during the denouement. The only good reason for using an epilogue is if there’s a big gap in time between the denouement and the last story question that needs closure. Then it might be appropriate to have an epilogue to close up that one last matter.
Unfortunately, many writers use the epilogue as an excuse to dwell on happily ever aftering. The epilogue of Harry Potter and the Deathly Hallows is one of these. J.K. Rowling is one of the best-selling authors of all time, and the Harry Potter series among the best-loved stories, but even she came under criticism for that epilogue, mainly because it was not necessary. Charming as it is to see Harry all grown up, you could skip the epilogue and not lose anything. Rowling’s editors let her get away with it because she’s a fantastically popular author, and fans love her characters. Without that fan base, an epilogue like that is unlikely to work.
Some authors use an epilogue as a teaser for the next book. The only reason for the existence of the epilogue is to set up a cliffhanger leading into the next book. Don’t do that. The story of each book should close at the end. An epilogue is meant to be the conclusion. Not a new opening.
This is part of what goes into a satisfying ending. The cliffhanger is the opposite of satisfying. The cliffhanger is nerve-racking.
If you have the sequel written, then you can include the prologue or chapter one of the next book as a teaser at the end of the first book — but call it that, because that’s what it is. Write the conclusion of Book One. The End. Turn page. Excerpt from Book Two. And this should, as much as possible, simply be a verbatim excerpt from the next book. At the end, if you have it, put the expected release date of the next book in the series. Once Book Two is published, update the e-book editions of Book One to include the link to Book Two.
So what’s the difference between an epilogue that’s a teaser for the next book and an excerpt that’s a teaser for the next book?
Reader expectation. The word epilogue sets the reader up for a conclusion. They’re ready for you to finish the story. If you instead use that opportunity to start a new story, the reader will feel cheated.
“Read on for an excerpt from Book Two,” however, tells the reader exactly what to expect. They can choose to skip it if they wish, because it is clearly identified as not part of the current story.
I’m hard-pressed to come up with an example of a really great epilogue. I’d love to hear of one.