I got your answer for you right up front. What’s the best way to show backstory? Don’t.
I’m not saying don’t have backstory. Have the heck out of it. Write up a 50,000 word manual meticulously detailing the history of your characters, your world, your interrelationships. Then take that manual and put it on the shelf. Let it seep into your subconscious but keep it as far away from your novel as possible. The only thing less interesting than expository is backstory expository. What’s interesting, what’s real, what’s urgent is the present: the now of your eye touching the word on the page and the moment coming alive for the reader between the characters and their story.
Say you’ve given some character a trait where she’s always flipping a coin. It’s a nervous habit. She flips it, she catches it, she doesn’t care if it’s heads or tails, she barely even knows she’s doing it. But you know. You know that twenty years ago after the house burned down and they were all outside watching the fire trucks your heroine saw her dad holding onto the one thing he saved other than his family—that near mint-condition Japanese yen his grandfather had brought back after the war. And something about the way it caught the firelight as every possession they owned went to hell, and the way her father comforted her with one hand and flipped that yen with the other while they waited for what seemed like ever under the orange midnight stars, all this still turns over and over like a crank in her subconscious so when she’s nervous or anxious or bored or turned on or ready to kill something, out comes the nearest coin. The reader doesn’t have to know any of this. But any time you write her into a scene that history will be there fidgeting with the change in her pocket, and your reader will feel it.
Everything your character does and everything he or she has become is a result of what came before. Your characters are the final draft of their backstories. If you’ve developed them with care behind the scenes and written them as fully-realized products of their pasts, then backstory will seep into your scenes in subtle and surprising ways. No one will be able to point to any specific place in your book and say, “there’s backstory”, but it will be there haunting your scenes the same way memories haunt our day-to-day. Your readers will tune into it and your characters will be rich and complex and painfully unaware of all the forces that motivate them—just like the rest of us.
Josh Wagner is the author of "Smashing Laptops" and "Deadwind Sea". He is also the creator of the Graphic Novel "Fiction Clemens" and several short stories in prose and comic form. His work in theater includes two full-length plays, several one-acts, and as producer and lead writer of the devised spectacle, "This Illusionment", currently in development. Wagner is an avid traveler and waster of time. He's still not sure what hit him.