"You kids are in and out more than a fiddler's elbow" when we would run in and out of the house playing.
"He's slower than molasses in January" when one of us would be pokey. And on the other hand "He disappeared like a fart in a gale of wind" when someone would speed off.
"If it isn't her ass, it's her elbow" about someone who would always complain of aches and pains. And the one I've found myself using with my own kids: "Don't look at me in that tone of voice!" because we didn't dare talk back but she knew we wanted to! LOL