Hospitals and compromised individuals are in need of face masks right now. I'm personally going to sew some and offer them for free on my neighborhood Facebook page. Hoping they will be useful to medical care professionals, etc. The following is a super simple tutorial that I made from looking at several other tutorials on line. There are so many DYIs out there if you don't like mine.
I am personally going to be making mine out of Harmony Art organic cotton since people will be breathing through them. But, whatever fabric you have on hand would be awesome! :) I'm using quilting cotton weight.
EDIT: Just read that these need to be 4 layers of fabric. NO PROBLEM. Just use 2 pieces of 9x15 inch fabric.