Three things smart people should stop saying

"It sounds like a cliche, but …" Nothing "sounds" cliche that isn't cliché. (Same goes for "trite.")
"It may sound corny, but …" "Corny" is love without the balls to let its freak flag fly.
"Words can't describe …" If words can't describe the feeling you're having, don't use words to tell us. Silence usually works far better.