One of the most challenging aspects of writing a novel or memoir is fitting in background information the reader needs to know without slowing down the story. If the story is a 3,000-meter race, than anytime you have to digress to explain a piece of back story, you are taking a detour. It slows the action down. If it isn’t done right, it can get the story off-track and lose the reader’s attention.
Only put in information that is necessary to the story: This may mean leaving out favorite bits about your or your character’s background. The cute story about Uncle Bill, who came to visit and short sheeted every bed in the house, may be a personal favorite but if your memoir is about the Vietnam War, it may not fit. You have to be as ruthlessly true as possible to your main story. If the information doesn’t fit, don’t use it.
Put in the back story stuff when it is needed or when it naturally comes up: For instance, if a character limps across the bar room floor on his way to wait on a creepy looking character in the corner, it is an opportune time to explain that he grew up during the London Blitz and his leg was crushed when a bomb fell on the house next door, collapsing it on his house and him. The character’s limping has created a question in the reader’s mind so rather than feeling derailed, the reader is grateful for the explanation. Sometimes, there is room for expansion: The bar tender’s mother had been killed in the bombing and he had been scarred for life growing up in a cruel foster home. And then, bring this digression back to the action: The skull-like head of the man in the corner reminded him of his drug-addicted foster father.
On the other hand, if your lead character is in the middle of a gun battle, it is not the time for him to think how his mother gave birth to him in a cattle shed and he grew up poor on the prairie.
Avoid phony set ups: Remembering is a funny thing in books. So often when characters or memoirists “remember” events or people or places, we find ourselves saying, “no way.” Authors often use memory as a device to get across back story stuff. Sometimes, it is completely random: Gazing out at the rose garden, Serena remembered the time she broke her leg falling out of the apple tree. Or, the English Tudor house made me think of the house I grew up in, a one-story rambler.
Sometimes set ups aren’t even necessary. The rhythm of a book will often allow for digression, and you can just include the information straight up: I was born thirty-six years earlier in a yurt on the Mongolian plain… You will often see back story at the beginning of the second chapter. A good first chapter will hook the reader, get him or her involved in the story, and raise questions that the reader wants answered. Then, in the second chapter, there is leeway for some back tracking.
Look for natural pauses in the action: When FBI agent Jim Snyder is on a stakeout, it is a good time to take a look at him as he sits there in his Chevrolet. He is wearing a cheap, rumbled suit and tie, but his tie clip is silver. It was a present from his mother. When he graduated from the academy, she had slid it on his tie. She had still been relatively youthful then… And so on into his past. Nothing is happening during the stakeout anyway and it has to go on for awhile before the plot unfolds again.