She smiled at him like a snake charming a snake charmer.
Her eyes danced like two shooting stars across the sky.
He felt as heavy as a 550 pound barbell 400 feet beneath the ocean.
The dog's tail wagged like a tsunami.
Another thing to be really careful of in fiction at all costs is personification. It's hard to do well. Examples of bad personification:
The scissors cut angrily into the paper.
The graffiti on the brick wall gloated boldly under the streetklamp.
With a quick jump, the dice hurled themselves across the table like two tiny square soldiers running from war (hey, bad personification AND a bad simile).