Below is a post by Dan Leohr that has a pic of his sister's mask she is making. No matter your "opinion" on whether a mask works or not, it is good to see people with craft skills and knowhow putting it to good use.

 Here's a few pics of the masks my gf is making and giving to rural elderly that are shut in. She makes them in a couple sizes and lengths, as well as elastic or tie. She'll likely start selling a few soon to get money to buy more supplies.