I won an honorable mention at the Poetry Revel a long time ago with this one.

This is a Shakespearean sonnet. Yes, most people write sonnets about how beautiful their lover's eyes are. I write them about my weapons.

Note the form: Three verses of ABAB rhyme and one of AA, all in iambic pentameter. Writing to fit a rigid form like this is in many ways easier than more free-form poetry, and good practice as well.