Penning a biography that reads like a short story is a form of narrative writing, a style that tells a story. This method has a plot, defined characters and a theme that reaches beyond the story. Using a short story to convey a biography limits space and how much of the person's life can be included, but it is suitable for the memoir of a specific experience or time period of the main character's life.
Choose what aspect, event or time period of a person's life to write about. Determine the beginning, middle and end of the experience; its conflict or problem; and how it was resolved. Focus on the experience you're retelling and include pertinent information about the character, but avoid wandering too far into other areas of his life. Doing this will leave you with a disjointed story going nowhere or with one that needs to be expanded into a novel.
Determine what the message or point of the story is. If writing about someone who overcame a challenge, the theme might be perseverance against the odds. Relating someone's adventure could inspire with a message of pursuing dreams. Sharing your grandparents' struggle to save their farm during the Depression could inform of the era's hardships. Weave the theme throughout the story by way of the characters' actions, conversations, thoughts, observations and conditions.
Decide if you will write in a first person or third person voice. First person (I and me) should be used if the narrator is also the protagonist, or main character, telling his own story. She can also be a secondary character relating a story that centers around the protagonist. The third person voice (he, she, they) is applied when the writer is expressing the words, thoughts and actions for the characters. Doing this for only one character is called third person limited while doing so for multiple characters is third person omniscient.
Engage the reader by introducing dimensional characters who are valid to the story instead of cluttering the manuscript with tidbits about every single person the characters know. Every character should have her part in telling the story. Include dialogue to move the story along, add interest and reveal aspects of the characters' personality or emotions. Transition from one character or scene to another rather than making abrupt shifts, resulting in a choppy, confusing read. Describe sights, sounds and smells as well as the thoughts, feelings and sensations a scene or setting inspires in the character.