Diane Gaudynski recently had a great post on how she makes feathers:
http://dianegaudynski.blogspot.com/
And I recently viewed some great Patsy Thompson videos online on free-form feathers (spine vs. no spine), but I can't locate where I saw them. :roll:
They're out there somewhere. ;-)
Here's her blog (and her DVD's are great):
http://www.patsythompsondesigns.com/blog/