@Andymat astonishingly I have not yet broken a needle sewing these, and they do all use metal toothed dress zips, from a bundle given to me a few years ago by an elderly lady who sewed lots in the 60s and 70s.
I've used a fairly chunky needle in the sewing machine, then when I've got near the zip teeth I took my foot off the pedal and either hand wound, or lifted the needle and then put it down again the other side of the zip. On others I tried sewing up to the zip then reversing and then turning round and sewing up to the zip from the other side.
Once I done the first line of stitching across the zip, I then cut the teeth out of the seam allowance area, so sewing the strip over the edge to prettify it was easier.