I stumbled upon a very effective method of "threatening" Emma a little while ago. When she is stalling or balking at a directive from me I start the count, "One, two..." That's usually as far as I get. She hustles on two. She always asks me, "What happens on three?"
Frankly, I don't know. I tell her, "You'll be punished." She always answers, "I don't want to be punished."
Somehow she intuitively knew that me saying "three" would be a bad thing. I didn't teach her that.
Whatever works, man.