I just finished up another batch to take to the office. Total count is at 505 masks. I'm use the Olsen pattern and put in a channel and use 12g copper wire. I've got a source of scrap wire from construction projects, it's stuff taken out of houses.
I usually lay my fabric out and cut four layers at a time with the rotary cutter. I cut strips for the mouth and side pieces, hem one long side and then cut them out, instead of hemming each small piece individually. I had yards and yards of shirt flannel in my stash that has been there for close to 20 years, and it's been nice finally finding a good use for it. Almost all of the masks I make have ties. I've been using extra wide quilt backing, cut 16" WOF, then I fold it and cut it into lengthwise strips at 1.25", sew then into tubes and turn (good thing to do while watching videos). I found that if I cut them width, the stretch makes it a lot harder to turn them. I can get about 80 ties per WOF, so enough for 40 masks.
I put the masks in ziplock bags, and add a 4" piece of copper wire. The bags are marked L and M, and people use the wire if they want, or leave it out. I always remove them to wash.
The nicest thing about sewing masks, don't have to pay attention to that pesky 1/4" seam allowance. But I worry I might get a be lazy about that when I get back to quilting.