I think that everyone should incorporate a signature accessory or signature type of accessory as part of their personal style. (For me I have a unique watch that I wear everyday.) It is pretty well known that Aria Montgomery’s is feather accessories. We have seen her sport them since the first episodes of the series.
Aria wears the Betsey Johnson Jungle Fever Feather Hoop Earrings.
Aria wears feather hair extensions. These can be professionally done at a salon, or you can purchase clip-on feather extensions.
These are an example of clip-on feather hair extensions. They are the Sultra Feather Hair Accents. (Other colours available.)
She has even worn feather earrings that aren’t real feathers at all.
If you are big into the feather trends the best place to get some feather earrings or extensions of your own is etsy.com. They sell many high quality and hand made earrings. Below is one of my favourites from etsy. It is the Sabelle Accessories Take Flight Single Feather Earring.