Katrine,
I really like the method that Sally Terry has come up with for making feathers. I want all my stitching to look free hand not like it came from a stencil. Do lots of practicing on paper with a pencil and if you can find large enough paper so you'll be drawing the same size that you'll be stitching on your quilt - all the better. You'll probably find it's easier for you to go one direction VS another. You make the vein first, I used my walking foot for that, but you wouldn't have to. Then you start from one end and make all the feathers on one side first, then go back and do the other side. I also like all the bazillion variations you can do to add variety to your feathers. Hope you have fun!