First of all, make a list of the consequences of shoplifting including how you feel about shoplifting itself and the people who do shoplift. Think about what the cost is to the people who do not shoplift as we must make up what the store loses by paying higher prices. Then, list several poetic devices such as simile, onomatopoeia such as the SLAM of the police car door, alliteration like the store's slip in my sweaty palm, personification such as the eyes of the door lock watching me, or any you think would fit in your poem and try to think of examples you could create. Then, I would write your poem WITHOUT RHYME and use free verse instead. Again, think of how you would like to prevent your little sister from being picked up for shoplifting, and use that emotion to dig deep to create your poem. What a great assignment!