When my children were little I made garments for them but now that they're grown I have been spending more sewing time making quilts and wall hangings. Hence, when I started making these masks I found very little ¼" elastic in my stash, and store supplies were depleted. I found that the flat headbands worked well, but they are all gone now, too. Today as I was trying to decide what to do I found that I did have a little ½" elastic left. I wondered if it could be cut in half and found that, YES, it could. So I was able to make a few more.
I added wire in the top edge of my masks so they could be form-fitted over the nose. Here's a video on what I did and I hope it helps!