Just in case you want to break a face touching habit or deal with a short trip out… adult size requires two pieces 9” x 6” fabric and two 7” pieces of skinny elastic
Update June 2020: I now interface one of the pieces of fabric to provide three layers and give a bit more structure …
To make: put the fabric pretty sides facing and sandwich the elastics inside with the ends poking out from the corners . Leave a 3” gap and stitch around the rest of the edge with a straight stitch. You don’t have to be too precise about seams as long as you sew over the ends of the elastic and keep the rest of the elastic well tucked inside.
Turn right sides out and then pin tucks roughly equal on each side. Three each side should do it.
Finally top stitch all the the way around to close the turn8ng gap and fix the tucks. You are done!