Step-by-step

Start with the pre-cut fabric (8.75×7.5"), and make a 1/4" seam along one of the short sides. One after the other, I cut them loose afterwards.
Use the jig to fold and sew the front and back pieces.
On one of the pieces, tape down the elastic on the good side. [I cut mine 7.75" long] Keep the tape away from the left, right and bottom edges. The tape can be re-used many times

[ If you're using bias tape, no tape is necessary ]

Alternatively, to make the model that I like best, cut a pair of 2"×4" pieces, and fold them double and iron them.

They get placed along the sides, fold towards the interior. Notice these sleeves are a little shorter than the back and front pieces. Align them with the side where the 1/4" seam is, as shown. This ensures that the other end stays open when you sew along the left, bottom, right.

After sewing and turning it right side out, I use a skewer to push the elastic (36") through the side sleeves, and then tie the ends together. (You can also put 2 small loops through there that fit over the ear)

Lay the other piece on top (not the seam on top), and pin at the location of the elastic. Sew the right, bottom and left. I do a little back-and-forth dance over the elastic.
Remove pins, turn inside out
Tape off, almost done
On the lighter side, I mark with pencil around the insert.
Leave an opening in the stitching to slip the nose piece in.  
Done!
Hubert van Hecke
Last modified: Thu Sep 17 14:14:40 MDT 2020