This question has options. How would someone go about accomplishing this goal?
How can I keep my western style hat from falling off my head without a strap?

Options:
(I) You can use adhesive backed foam weather stripping applied to the front and back of the hat on the inside to make it a more secure fit.
(II) You can use adhesive backed foam weather stripping applied to the front and back of the hat on the outside to make it a more secure fit.
(I)