Even a non-fiction book needs to tell a STORY. If it doesn't tell a story, then it falls into the boring, only going to be read as a requirement, academic text book category.
Sometimes writers get so caught up in telling the story that we lose sight of what STORY is really about.
Merriam-Webster's Dictionary defines STORY as:
a: history; to narrate or describe in story
2 : an account of incidents or events
b : a statement regarding the facts pertinent to a situation in question
c : anecdote; especially : an amusing one
3.: a fictional narrative shorter than a novel; specifically : short story
b : the intrigue or plot of a narrative or dramatic work
4: a widely circulated rumor
7: a news article or broadcast
Every STORY must have a beginning, middle, and an end.
One of Jack Bickham's favorite examples of a simple, basic story was: Girl sees boy. Girl wants boy. Girl gets boy.
It's short. It's grammatically correct. It's non-superfluous. It's the basic outline for every romance novel ever written.
The story begins when the girl sees the boy. Then middle of the story is the girl acting upon her desire to make the boy her boyfriend. The story ends when the girl and boy finally get together and live happily ever after. In a dark romance it would end when the girl decides she never really wanted that boy in the first place, so she kills him.
Every story is about desire.
The protagonist wants something. They spend the entire story doing whatever they need to do in order to get what they want. The antagonist tries to prevent the hero from getting what he desires. In the end, the major character either gets what they wanted or they don't.
The beginning of the story is the appetizer:
Just enough to whet the reader's appetite, but not enough to fill them up so much they won't have room left for the main course.
The story doesn't start when the protagonist is born, or two years before the main event of the story. It starts moments before the major event, or in the middle of the major event, of the story.
What happens before the girl sees the boy is irrelevant to the story. It doesn't matter where she grew up, who was her best friend in fifth grade, or what she studied in college. It doesn't matter what she does for a living, or where she lives, or what she had for breakfast.
What matters is how she feels when she sees the boy.
It's okay to set up the scenario. Set the scene. Show the reader where the girl is at, who she's with, what she's doing, and how she feels right before she sees the boy. Anything that happens more than a few hours before she sees him for the first time is back-story.
Back-story should be treated like the "previously on" introductions to a television show: brief, concise, and related to what is about to happen in the current episode. The "previously on our show" portion does not recap the last five seasons of the series. The back-story of a book should not attempt to recap the last five years of the protagonist's life.
If back-story is relevant to what is happening during the story, then weave it through the story like a single thread in a tapestry.
Some authors use flashbacks to reveal back-story. Flashbacks interrupt the flow of the story the way commercials interrupt an episode of a television program. Consider product placement instead of commercials. What's happening in the current story can remind the character of something that happened in the past, but they don't have to relive the old story, they can just acknowledge they've been there done that before.
The middle of the story is the main course:
It should be filling and satisfying. It's the perfect sandwich smothered in limitless toppings, with skillfully trimmed edges, dripping with sloppy, special sauce, accompanied by a side of fries and onion rings.
Just because the girl wants the boy doesn't mean she's going to get him without a fight. He may already have a girlfriend. His girlfriend might be her sister, or best friend. When she first sees him he may be boarding a plane to some far away land, forcing her to climb mountains, cross oceans, or travel to the stars to find him again. Her journey should be messy, treacherous, adventurous, fantastic, and frustrating. Even after she finds him she may need to fight to win him over. There should never be a dull moment.
The end of the story is the dessert.
Nothing is sweeter than a happy ending where the couple kisses, at sunset, on a beach, as the credits roll up the screen.
The author is the Chef. They plan the menu, shop for ingredients, and add spices, to create a sumptuous, appetizing, satisfying meal for their readers.
The editor is the Sous Chef. They remind the Chef that white goes with the fish, red with the steak. They suggest which sides go best with the main dish. They make certain nothing burns, and soufflés don't fall. They clean up the messes and throw out the leftovers.
Together the author and the editor serve the reader an unforgettable banquet.
No matter how they spice it up, it all begins with a simple, basic STORY. Girl sees boy. Girl wants boy. Girl gets boy. Everything else is icing on the cake.