trite, hackneyed, stereotyped, tired, worn out. Kind of like a tv program one's children have watched...and watched...and watched some more.
In other words, find another way to say it. If you think your phase is unique, try a search for it at ClicheSite.com: Clichés, Sayings, Phrases & Figures of Speech to find out for sure. It's a fun resource.A few examples:
- a dime a dozen - Yes, I used this one, but I swear it was only to make a point.
- cool as a cucumber - Psst...do you really want to compare your hero to a cucumber?
- a rose by any other name would smell as sweet - Maybe, but because of overuse, it's trite.
- ants in his pants - I sure hope not!
- kick the bucket - If it's your hero or heroine, it's not allowed in a romance.
- know it like the back of my hand - Your plot? You'd better--I learned my lesson on this one the hard way.
- up the ante - Always a good idea when you feel your plot is struggling.
Another useful cliché site is Cliché Finder. Bare bones, but easy to use site.