One way to think about your ending is to revisit what you've written so far and consider what readers still need to know. Zachary Petit of Writer's Digest says that one way to do this is to think of the story as a series of promises to your audience. As you read it, consider any questions you've failed to answer, suspense that fails to pay off or unaddressed character issues. Petit says that good writing isn't out to "trick" readers; it creates a fascinating, fluent story that leaves behind no loose ends.
Award-winning short story writer Sarah Selecky has a surprising piece of advice for writers: write a bad ending on purpose. Often, writers become so paralyzed by crafting the perfect finale that they can't write at all. Selecky says that if you let yourself write an ending that's ridiculous, melodramatic and unrealistic, you release the psychological pressure of finishing the story and free yourself to write the conclusion it's meant to have. Your characters may not live happily ever after or die in a fiery inferno in the final draft, but these experimental endings can at least help you clear your head.
According to Brian Scott of the writing advice website Freelance Writing, a good short story features a central character who undergoes change from beginning to end. If you're struggling with the ending, it could be because you haven't sufficiently developed your character. By reviewing the story, you can decide what fate would be most appropriate, satisfying and effective for readers. This also applies to creating successful antagonists. All characters in your story need to maintain the same traits you've established throughout and lead to a conclusion that completes the arc of their development.
Many writers bring their short stories full circle by crafting endings that mirror the opening. Kathy Kennedy and Dennis G. Jerz of Seton Hill University say endings that reflect the beginning can show how the story's events have changed or not changed the characters. For example, Flannery O'Connor's "The Life You Save May Be Your Own" opens with Mr. Shiftlet, a drifter, driving up to the home of Lucynell Crater and her mentally disabled daughter. By the end, Shiftlet has taken advantage of the family's generosity, married the daughter for money, and abandoned her at a truck stop. The story ends with him driving away, mirroring his arrival at the beginning.