Ingredients of a Short Story Discussed by HG Nadel If you are writing a short story, you need two main ingredients: characters and plot. You must have people*, and they must be doing something.
[*Animal stories succeed because of anthropomorphism, which is when human shapes or characteristics are given to a god, animal or inanimate thing. The old stories of the Greek gods employed this means of enlivening their subjects. Children's stories use it often.]
Most writers advise starting with the characters. Create powerful and interesting characters, and then put them into situations involving conflict and/or difficulty of some kind which they have to work through and that becomes your plot.
Here are some guidelines by HG Nadel for your characters:
The short story should have only two or maybe three main characters. These main characters will only deal with a few relevant aspects of their character, and may be scarcely described, leaving that to the reader's imagination, unless it is crucial to the story. In a short story, you don't have room for extensive descriptions Any other characters involved need not even be named, let alone described - they're the supporting cast only.