PLEASE NOTE: There is no one face mask pattern to rule them all. Before sewing face masks for an organization please click on the link associated with that organization to ensure that you follow their specifications. In the event that an organization doesn’t provide a link to a pattern or sufficient guidance below are some links that we have seen organizations reference:
Button Counter’s Facemask: A Picture Tutorial
The FreeSewing Open Source Project’s Face Mask Pattern and Tutorial
The Stitching Scientist’s Face Mask Tutorial
The Turban Project’s Face Mask Instructions and Patterns
One of the things we have seen the least amount of guidance on is what fabrics/textiles should be used for cloth masks. The folks over at Project Cloth Masks provide some excellent guidance that has been vetted by engineers and medical professionals.