The Cdcs I've tied with plastic Netty bags that you get fruit and veg in, there are about 8 different colours also I have brushed the bodies with 2 coats of Veniard No1 varnish.
I have also tied 5 plumes of natural Cdc with the stalks left in each fly, as I've been fishing them in rough water and catching fish, but on the whole I've fished 2, 1, gold holographic material body with olive thorax, and 1, black body with a silver rib and fluorescent red thorax, over the last 4 months these 2 patterns have not failed even if I've missed or lost the fish, my hook size are 10s.
One last thing which may be controversial is I Gink the Cdc with a drop of Gehrke'ss Gink then when I catch a fish I wash it then dry it with a PAPER TOWEL all the lads where I fish do this as the fishes slime doesn't cover the ginked part and wipe the fly on the towel like a paint brush it's a very fast way of drying your fly. The fly is only ginked once when you start.
Robbie