In Textiles, how do you properly attach a zip to the back of a costume/dress?

It's a while since I did it but I used to use a long stitch on the sewing m/c to close the seam where the zip would go. Then I would open out the sides of the seam, tack the closed zip to the inside, sew it in(with a normal stitch) and then slit open the seam on the outside. Voila - the neatest zip you ever saw!