1. Research is essential, but experience is the only thing that can yield authenticity.
2. Imagine situation and scenes, jot them down in a notebook.
3. Whatever you cut, keep -- in an organized way -- for use in other stories.
4. Elicit emotion by showing action, character reactions & other effects; rarely by telling.
5. Every action and scene must move the story forward; even intentional red herrings (as with crime or mysteries) are needful but MUST have have purpose beyond being merely interesting.