There are 5 different ideas: Pipe Cleaner, Elastic with sewn-on buttons, Grosgrain Ribbon with sewn-on buttons, Grosgrain Ribbon with snaps, and Hook & Loop (velcro).
Click image to view full size:
Click on the following links for individual instructions for making each type of Comfort Band:
Elastic and Buttons
https://joyfulrosedesigns.blogspot.com/2020/04/joyfulrose-face-mask-comfort-bands.html
Ribbon and Buttons:
https://joyfulrosedesigns.blogspot.com/2020/04/joyfulrose-face-mask-comfort-bands_10.html
Ribbon and Snaps:
https://joyfulrosedesigns.blogspot.com/2020/04/face-mask-comfort-bands-ribbon-and-snaps.html
Hook and Loop (Velcro):
https://joyfulrosedesigns.blogspot.com/2020/04/face-mask-comfort-bands-hook-and-loop.html