Don't make that face or it'll freeze in that position.
Be careful or you'll put your eye out.
What if everyone jumped off a cliff? Would you do it, too?
You have enough dirt behind those ears to grow potatoes!
Close that door! Were you born in a barn?
If you can't say something nice, don't say anything at all.
Don't put that in your mouth; you don't know where it's been!