"Flake" the sail from the bottom to the top. With the sail laid out and a helper at the clew and you at the tack, reach up about 3', grab the sail with your arm closest to the head, while holding down the sail at about 18" up with your other hand, giving the sail a Z-fold. Repeat as necessary until the sail is completely folded.
Roll it from clew to tack, so that the sailmaker's patch shows. (Notice that the patch should have the sail type (H16 Main), color pattern (Misty) and sail number written in pencil on the patch.)
That's how it's done at the factory.
