End with an epiphany. An epiphany is the moment when your character has a sudden insight into the meaning of something. For instance, Dickens’ Ebenezer Scrooge realizes the error of his ways after being shown his own grave. The epiphany doesn’t necessarily occur at the ending of a tale (though it can), but serves as a means to pull together various themes in the story. An epiphany offers a way for you to end your story on a strong and emotional note.
Have the character achieve his goals. Your character will want something and will spend the majority of the story trying to get it. The ending or climax of the story occurs when the character gets what he wants. For instance, if the character is pursuing a girl he loves, end the story with his winning her heart.
Have the character fail to achieve his goals. Stories don’t necessarily have to have happy endings. A character can fail to reach his objectives, but still have an epiphany due to his failure. For instance, he might fail to win the girl’s heart but ultimately realize that she wasn’t his intended true love after all. Perhaps he realizes that the girl wasn’t who he thought she was in the beginning (cruel and selfish instead of sweet and generous) and falls out of love with her.
Have something dramatic happen to the character. Perhaps a friend or family member dies unexpectedly, forcing the character to reevaluate his beliefs and ideas. In F. Scott Fitzgerald’s "The Great Gatsby," Jay Gatsby is shot and left for dead in his swimming pool. His death forces the narrator, Nick Carraway, to reevaluate who he is as an individual and his relationship with Gatsby.
End with a moral. While morals tend to be old-fashioned and more suited to fairy tales, they can still be an effective way to end a story as long as you use a subtle touch. Modern readers hate to be preached to, so avoid using a heavy-handed or obvious moral ending for your story.
End with a great image, a reference to your story’s title or evocative language. Each of these should pull together the themes of your story and wrap them up in a concise way. For instance, in "The Great Gatsby," Fitzgerald ends the story with Nick reflecting on a green light shining at the end of a pier. The green light symbolizes the themes in the story, but it also leaves an indelible image in the reader’s mind. If your story is called “Sheets,” end it by referring to sheets in a way that pulls together the story’s meaning.
End with dramatic irony. In Flannery O'Connor's "Good Country People," for instance, the main character sets out to "corrupt" an innocent young Bible salesman, only to learn that the Bible salesman, who turns out not to be so innocent after all, has conned her. Dramatic irony sets up expectations in the reader's mind and turns the tables on them in a memorable way.
End with a surprise. For instance, a man who thinks he's happily married learns that his wife wants a divorce. In the movie "The Others," a young family thinks they are living in a haunted house, only to learn that they are the ones who are dead.