Feathers in headgear date back many years, sometimes indicating the number of enemies killed in battle or other times they were taken from a woman's hat as a sign of affection. Cowboys -- or those enamored with the style -- can place a feather in their cap for any number of reasons.
Insert the feather's quill directly through the hat band. This works well if the band has a more open weave.
Hot glue the feather to the inside of the hat band as an alternative attachment method. If you don't want the glue to accidentally get on your hat, remove the band first.
Clip the feather to the hat band or brim using a clip. This style is is reminiscent of Native American Western hat wear, and provides the fastest and easiest attachment method.