Working on the better than nothing principle.
Underwired bras, padded cups with a foam layer and an outside layer, a pocket for padding are roughly the right shape. Cutting off the elastic with the strap adjuster, separating the cups, trim to shape.
I read about doctors using salt water
www.google.com/amp/s/www.businessinsider.com/mask-coated-in-salt-neutralizes-viruses-like-coronavirus-2020-2%3famp
So I soaked coffee filters in salt solution, dried with a hairdryer. Inserted in the pocket or between layers.
Putting the underwired under the chin, sewing elastic from the straps at the sides. It was fast, and better than nothing.
I tied a bandanna cowboy style over my masked face, covering my nose to neck.
Currently jokes about looking like a tit...but...
As long as you remove carefully, wash mask in bleach, destroy coffee filter, it might just might be better than nothing in a pinch.