The purpose of a narrative essay is to descriptively narrate a story. Do your best to include descriptive vocabulary words so that your reader can imagine the setting--show rather than tell.
To narrate a story, you need to form an outline that follows a timeline, so that you're not jumping back and forth through different sections of your topic.
You need to build a climax and include action, then subtly bring it to an end.
Try to describe exciting facts for a longer period of time than basic, uninteresting ones. And make sure that your essay is fit for the audience and will capture their attention!