Writing a narrative essay is an essential talent for field research. Rather than summing things up for your reader, it presents your experience and allows them to draw their own conclusions. The narrative essay makes it point by subtly guiding the reader, rather than battering them the way a rhetorical essay would.
MLA format recommends including citations in the text, but in a narrative essay this is disruptive. If a work was helpful, cite it in a ‘Works Consulted’ list after the essay. Explain yourself as you go along, rather than trying to refer your reader back to a previous statement.