Some nice analogies taken from high school essays:
Her face was a perfect oval, like a circle that had its two sides gently compressed by a ThighMaster.
His thoughts tumbled in his head, making and breaking alliances like underpants in a dryer without Cling Free.
She grew on him like she was a colony of E. Coli, and he was room-temperature Canadian beef.
She had a deep, throaty, genuine laugh, like that sound a dog makes just before it throws up.
Her vocabulary was as bad as, like, whatever.
McBride fell 12 stories, hitting the pavement like a Hefty bag filled with vegetable soup.
Her hair glistened in the rain like a nose hair after a sneeze.
The hailstones leaped from the pavement, just like maggots when you fry them in hot grease.
Even in his last years, Granddad had a mind like a steel trap, only one that had been left out so long it had rusted shut.
Shots rang out, as shots are wont to do.
The plan was simple, like my brother-in-law Phil. But unlike Phil, this plan just might work.
The young fighter had a hungry look, the kind you get from not eating for a while.
He was as lame as a duck. Not the metaphorical lame duck, either, but a real duck that was actually lame, maybe from stepping on a land mine or something.
The ballerina rose gracefully en Pointe and extended one slender leg behind her, like a dog at a fire hydrant.
He was deeply in love. When she spoke, he thought he heard bells, as if she were a garbage truck backing up.