Terry Bisson’s Rules for Writers (of SF Short Stories):
37. No wizards or dragons. They will make your short story seem like a part of a longer, less interesting piece.
38. Don’t meander or digress. You can pretend to meander for misdirection. See below.
39. Misdirection is interesting. SF readers like puzzles.
40. Fights are only interesting in real life. They are boring in stories.
41. Novels are made out of characters and events. Short stories are made out of words alone. They are all surface. Polish.
42. Plot is important only in time travel stories. They must have a paradox. This limits their range severely.
43. Symmetry is more important than plot. A short story must make a pleasing shape, and close with a click.