Back in March, I started making masks to donate and sell. I was observant in public to see what kinds of masks people were wearing and made several designs before finding one that was both effective and comfortable. The big debate, for me, was to employ head straps or ear loops. This design accommodates either!
Fold the rounded edges into one another and smooth out the mask with the good stuff on the inside. Sew along the bottom of the mask using a straight stitch and turn the mask inside out. Use an iron to press the edges of the mask before continuing with the next step.
Fold over about 1/4″ on the end of each unfinished edge and press. Sew along the edge of the fold, leaving room for elastic.
Use a safety pin to help guide the elastic through the sewn down fold. Tie a knot in the elastic ends to fit. Another way to “string” the mask would be to put in long ribbons on each side and using them as head straps instead of ear loops.