Here's a fly video that might be of interest http://www.theweeklyfly.com/TWF/2013...bunny-dun-8-06. Notice that he doesn't stack the hair and uses the fuzzy underfur rather than just guard hairs for the wing. I believe that helps with buoyancy (traps air) as well as adding bulk. Also note that he trims the wing to length and shape.

I tie my snowshoe caddis wings in a somewhat similar manner -- leave most of the underfur, tie it long, and then trim to length / shape.