How do you come up with Jace’s funny lines?

EB White once said: “Explaining a joke is like dissecting a frog. You understand it better but the frog dies in the process.” The answer is: I don’t really know. I have a lot of funny friends. I am very sarcastic myself. I keep my ears out for funny conversations my friends have and often adapt aspects of them for my books. If you really want to learn how to write humor, there are books out there about it, although I tend to think either you have an ear for what’s funny — which is generally about timing and word choice — or you don’t.