First prototype down, and I have a lot figured out. (Got this pattern from the book Sew Retro, btw. Credit to them for the template.)
So, all the fabric has to be cotton. I used satin for the underside in hopes to improve quality, but slippery fabrics do not hold in MY hair, much less anyone else. So, lesson 1 learned. Cotton.
Secondly, I learned how much elastic to use in the back. The pattern called for a thinner elastic in 5 inches. I purchased a thicker elastic, but it requires more length. 7 inches or more. Lesson 2 learned.
Third. The hand stitched closure is a pain with craft strength interfacing.