Identify what you want your narrative poem to be about and what the story's theme should be. To help with this process, glance over a book of quotations or another work of poetry to see what stands out and is appealing, and use this as a guide for your own writing. Also, think about snapshots of your own experiences that could serve as a good narrative poem storyline, and gather sensory details about those experiences.
Brainstorm for ideas about your main character. Determine whether you want the protagonist to be a person or an animal. Then, create paragraphs describing each character, explaining their personality traits, family history or other background information that might be helpful for the story. Also, determine who will be the speaker of the poem.
Create an outline that delineates the inner and outer conflicts of the main character or other characters you have created and what you want to happen to each one throughout the story, according to Textetc.com. This will help you to solidify your plot and the setting--the time and place--of your narrative poem. Identify the plot's rising action, climax and falling action, according to Babinlearn.com, an education site for students. Then, determine how you want the conflicts to be resolved.
Identify how many stanzas you want the poem to be and break up your storyline into these stanzas. Also, determine if you want your lines to rhyme and how they rhyme, or if you want the poem to have a set meter or be a little varied. However, these elements are not necessary for a successful narrative poem.
Determine how you want to start the narrative poem by identifying an event that will set the stage for the storyline. Make this event one that conveys the image you want the readers to have in their minds and the emotion or feel you want to depict at the beginning of the story.
As you begin to write your poem, use expressive and meaningful words and adjectives to help develop the big picture. For example, instead of simply saying that a "child chased the ball," describe the action in more detail by describing how the child looked, how he or she ran after the ball and what the size and color of the ball was. Use a thesaurus to help find more attractive synonyms for common words.
Read over your poem, and rework any lines, stanza by stanza, to add more humor, descriptions, catchy phrases or other elements that make the narrative better. Then, include a title that adds to the meaning of the poem.