Probably the greatest danger in writing flash fiction is the urge to summarize your story, to put the burden of narrative movement on exposition because flash fiction is so short. That is usually (although not always) a mistake.
Prose is made up of three elements: description, dialogue and exposition. Exposition explains. Exposition contracts (speeds up) time. Exposition is telling. Now exposition definitely has its uses. This blog post is all exposition. Just remember this. The more exposition in your story, the more it reads like an essay.
Here’s a good rule of thumb for writing flash fiction: show don’t tell.
The scene allows you to show your story. A scene is made up mainly of action (dialogue is action, too) and description. A scene shows your characters inter-acting with each other. The scene gives your characters the chance to act out in the imagination of your reader what you story is all about; and when your reader’s imagination is engaged, the reader becomes invested in your story.
(Now let’s step back for a moment. Of course, you can mix in exposition in a scene. I’m just trying to emphasize that action is what carries the narrative movement of a scene. Okay?)
Because flash fiction is so short, one or two scenes are usually enough to move your story from the setup to the payoff. Three scenes may be the limit. After three scenes your story will probably be in danger of being too fragmented.
So, exposition is good. Exposition is necessary. Exposition can be a powerful literary device in the toolbox of the flash fiction writer; but the scene is where the action is, literally.
Show don’t tell.
PS This blog post is not meant to be a list of hard fast rules on how to write flash fiction. I’ve read many writers who use exposition for narrative movement. This post is to get you to think. Above all else, a writer must think.