Is the anecdote strong enough to use for a story? What might have been interesting to you, your spouse or friends might not be so for a reading audience. What is it about the anecdote that you think can be fleshed out into a longer story? Does it say something interesting about people? About life?
What elements are in the anecdote that you can flesh out into a short story? For instance, does your anecdote contain interesting characters or a shocking incident, say a traffic accident you witnessed? If so, start from there and build a story around it. If the anecdote contains an interesting character, such as a funny co-worker or a strange neighbor, focus on him or her as the protagonist in your story.
Build a short story around the anecdote. Anecdotes often exist as little moments, such as a funny conversation you’ve had with your mother or an incident you’ve witnessed on your way to work. But short stories must have beginnings, middles, and ends in order to be complete. Something must happen in your story. For instance, the anecdote about the traffic accident can be witnessed by a character who’s deciding whether to leave an unhealthy relationship. Here, the anecdote can be used to tell a broader story about the character and her relationship.
Use fictional elements with which to build your short story. That means your story should have character development, a plot, narrative, descriptions, and other fictional elements that make up a good short story. If your anecdote is sketchy, then you’re going to have to flesh it out.
Use the anecdote as a scene in your story. Use it as the beginning of your story or build the story toward that scene. Make sure that the anecdote works as a scene--description, dialogue, etc.
Tell anecdotes through flash fiction--short, short stories. For instance, that funny conversation or the traffic accident can be turned into good flash fiction. But you still must use all the fictional elements of storytelling in order for the story to feel complete.