Matt,
Definately burn the detail on feathers. That is all I use when doing the primaries, secondaries, tertials, etc.. When doing the softer looking feathers on the chest 'belly, and mantle, I use the dremel tool with a small stone. It gives them a softer fluffier look.
Birds are what I carve the most. I started out doing ducks but I enjoy doing songbirds more. I found that the ducks were all too similar.
Let me know if you have any more questions.
Chris
