Like Wolftracks I have used feathers in crafts for years, even before I had my own birds. ditto what others say about preserving the skin with Borax. I would add that skins will keep better if you remove any flesh or fat from the messy side of the skin. You can use a spoon to get most of it.
I heard about the hair feather fad right here on BYC a month ago. Someone was warning folks to beware at county fairs, because teenagers are cutting tail swords for their hair. Funny thing was, I was getting a haircut a few days later, in Stanton KY. I JOKED about this city fad and the lady actually said it was all the latest rage, and pulled some out of a drawer. She was going to try and make some herself, but was having trouble. So I showed her some tricks.
Hackle is what everyone wants, but other parts can work. The major obstacle is the quill. Archers do not see this as a problem. Tail swords or wing feathers can be "stripped", the pretty part peeled away from the quill like the peel off a banana. Then the little remaining strip can be trimmed to shape, curled, dyed or heaven knows what. The act of curling the quill, pulling it across a scissors, also cleans away any remaining pith and limbers things up.
I was under the impression fly tyers really don't want the natural oils removed from their feathers. Bleach would be a major mistake. Definitely use a little shampoo and blow dry. Some also cycle the feathers in and out of the freezer to kill any hitchikers.