Another trap is the concept that a writer doesn't have to know exactly what he or she is saying. Writers forget at their peril that they have brains. Much of the hard work in writing is in the thinking, and it pays to work out your ideas clearly before you start. There is no substitute for knowing what you want to say and how to take the story from start to finish without the wheels falling off. Most modern short stories have simple narratives or, sometimes, no story at all.
Short stories tend to be about a revelation.
Something that is revealing about a character, place or time either happens in the course of the story or has happened in the past. The exact nature of the event is virtually never stated. It remains both elusive and allusive. We know about it only because it is either implied or intimated, and there will usually be a quality of ambiguity about what has happened and why. In most cases, a story derives its tension from the way it works toward this all-important moment.