Witchipedia

Well… what do you want them to be? Some might use them to represent the element of Air. Or you could use them to bring in attributes of the animal they came from. A crow or raven, for example is often viewed as a messenger between worlds and a pigeon has a long history of being used as a messenger between people, so you could use their feathers in spells related to ensuring that messages are received, or well-received.

People also dye feathers different colors and use them to bring color into a spell.

Feathers can also be used as tools, to move smoke during fumigation or to dust an area like a mini besom feather duster, perhaps.

Certain feathers can also be used to represent deities with whom they are associated. You could keep crow feathers on your shrine to The Morrigan. I keep peacock feathers on my shrine to Hera.