The essay needs a thesis or underlying idea to explain the significance of the narrative. This is what makes a narrative essay different from a story. For example, if you write about being in a car accident, that's just a story, but if you write about your car accident experience to illustrate the importance of safety belt laws, that's a narrative essay.
In narrative essays, the thesis doesn't need to be stated outright; the thesis can be "implied." Avoid generic, throwaway theses such as, "I learned a lot," "It was the most important day/experience of my life" or "I'll always remember."
In addition to the story elements, a narrative essay should contain facts and information from academic sources. Look for statistics, scientific findings and even dissenting opinions to give credibility to your argument.
You should carefully consider how you reveal your story in the essay. Most authors break up a story with bits of research where they are relevant. The structure of the story should contribute to the reading experience. Some authors tell the end of the story first to catch the reader's attention. Other authors withhold the outcome of the story until the very end to create suspense. Whichever way you choose to tell your narrative, avoid long, drawn-out paragraphs that provide too much detail; these slow down your essay.
Although many students use first person in narrative essays to talk about their own experiences, you can also write a narrative essay using someone else's story in the third person. It can be the story of someone close to you or someone you've researched thoroughly. Be sure to only include details that you can factually or reasonably prove.