...don't try again so confidently.
My sister and I made macarons a couple of weeks ago--successfully, too, for a first time effort and with a notoriously difficult recipe (I think all macaron recipes are: they have such a delicate, tricky structure).
Yet yesterday, when I attempted them again, I only ended up with six. (And it took five hours and I used nearly a dozen eggs).
I think I'll use a different recipe next time--or not intend to gift them. You know, just in case.