A long-standing book series can be a fantastic way to build your audience. 

Spending more than one book with beloved characters, building their arcs over time, is an organic way for readers to think of you not just as “that person who wrote that one book I liked” but as “the author of my favorite series!” And the genres that most often lend themselves to long-running series —mystery, romance, and fantasy—are some of the markets where indie writers are best able to make a real career. 

But a series isn’t simply recycling the same story over and over. And if you don’t take your sometimes book-length story arcs seriously, you might turn readers off, even if they loved your first installment. 

Don’t treat a series as an excuse to churn out material without putting in any care. There are three key factors to keep in mind if you want to make sure you don’t lose sight of what makes your series worth spanning multiple books. 

Let Your Characters Develop 

We are who we are because of our experiences; that’s true of real people, and it’s true of fictional characters. If your characters are sticking around past one, two, or three books, then they’re going to start collecting a whole lot of experiences. If they remain the exact same as they were on page one of book one, your reader is going to feel unsatisfied. 

Now, that doesn’t mean that they become completely different people. They just might make different choices, or if they stick to their ways, it might be for different reasons. Maybe your amateur gumshoe, who started off the series determined to stick to their job as an accountant, decides to explore what it would mean to get a private detective’s license after solving so many mysteries. Maybe your wizard, who has navigated court intrigue and royal disasters for a few books, wants to take a break from politics and journey into the wilderness. 

If you keep putting off letting your characters grow, your readers will feel as if you’re writing the same story over and over. You can stretch out a good will-they-won’t-they relationship for a few stories, but eventually readers are going to wonder why two people who have such chemistry don’t just get together.

Good characters are active—they make choices. And what you put them through, as the author, will inform new and exciting choices for them to make later on. 

Explore New Places

A natural consequence of following your characters through their fictional lives is that you’ll go to new places. A city dweller moves to the country for a change of scenery, or vice versa. There will be a lot of new material for your epic fantasy if the aforementioned court wizard encounters some not-so-peaceful elves surrounding his forest cabin. 

But for some series, the setting itself is a character, and authors may be reluctant to leave it behind. Many cozy mystery series are set in a very specific small town. Romance series often move within a set community in a set place. 

But there’s still room to explore new settings even within those kinds of series. Louise Penny’s iconic Chief Inspector Gamache series is at home in the fictional town of Three Pines, but not every single book is set there. Characters may go on vacation, visit relatives, or go to school. If your series has a specific setting as its home, going to a new place can be a special trip for the series itself as much as it is for your characters. 

It’s great to have a setting that serves as its own character, but don’t let those boundaries keep you walled in.

Give Your Series a Heart

As you explore new and exciting ways to keep your series fresh, don’t forget to keep one thing the same: the heart of your story. 

There has to be a reason that your series is a series, published in a particular order, and not simply a backlist of books where the characters all have the same names. The hard-boiled detective who is driven to solve unsolvable murders because he could never find his wife’s killer might move through different stages of grief as books progress. He might even develop new relationships and/or learn how to have a healthier one with his work. But he’ll probably always be motivated to protect the people he loves.

If your court wizard’s belief in the importance of protecting the public is shaken, it’ll likely be crucial to your series that his faith is later renewed. Your romance series that bops between the residents of an enchanting seaside town will always have the common theme of love blooming when you don’t expect it. 

Think of your series’ heart as the reason that a trilogy simply wasn’t enough. Keep that heart in mind while you follow your characters and bring new and exciting places to life, and you’ll find that every new installment in your series makes your career stronger and stronger. 

Chelsea Ennen is a writer living in Brooklyn with her husband and her dog. When not writing or reading, she is a fiber and textile artist who sews, knits, crochets, weaves, and spins.