I found this swans flight feather yesterday so decided to make a fishing float, using the feather, a piece of flint and a piece of Stinging Nettle stem.
First the feather needs to be trimmed to leave just the quill. There are two methods of doing this; One method is to cut them off with a piece of flint
and the other is to start at the top of the feather and pull removing a thin strip of membrane along the edge of the quill
When you are left with just the quill decide one the length of float you require and then this down the quill by scraping or cutting it with the piece of flint.
Then fold the quill at the point where you have thinned it
I used a piece of nettle stem as a lashing to hold the two pieces together (the nettle should be waterproofed with resin or something similar).
The float is now completed
and ready to use