In a short story I wrote a few years back, I placed a scene in the middle that takes place on a corner in New Orleans in the French Quarter. It was intended as nothing more than a "try-again, fail" point in the story. Yet that one scene is what everyone remembers about the story. I thought of it as trivial, yet I always get the most comments on it's details, on the trivia that appears in the scene to cement it to reality.
Many writers stop the story with trivia, you've read them, a character enters the room at a run, but before they can take another step, the writer tells you everything about them right then and there like the story can be slowed in the lens of a stop-motion camera; the color of their hair and eyes and lips, the brand name of the jacket they're wearing, the size of their shoes, even the name of the cologne they've bathed-in. Half a page or more later, the camera starts-up again and we're expected to remember the reason they ran into the room in the first place.
Yet trivia can be a writer's best friend. Without knowing something about the scenery of the story it becomes a simple, lifeless, fable. I want to know where in the world the story takes place and I want to know by hearing about the little things that make it all real and unique. Likewise, I want to know enough about the characters to be able to visualize them in my mind, but not so much that I get bogged down in more than what I would notice in the course of action in real time. Don't tell me that the teenager has three zits (only?) and exactly where they are if they don't move the story along.
Like Shirley Jackson said, "Try to remember with description that you must never just let it lie there; nothing in your story should ever be static unless you have a very good reason indeed for keeping your reader still; the essence of the story is motion. Do not let your chair be 'a straight chair, with no arm and a hard wooden seat.' Let your heroine go over and take a firm hold of the back of a straight wooden chair, because at the moment, it is stronger than she." (from "Notes to a Young Writer" in Come Along With Me)