The muddler has become my go to fly and come back fly. Summer Steelhead can't resist it, when nothing else seems to be working, leading me to develop a tremendous amount of confidence when fishing this hairy little critter, it seems to work almost every time.
The last few years I've tied dozens of muddlers, using size 6, 8, and 10 hooks work the best. As for materials just be creative as Marty would say. Marty and I started tying tube muddlers a few years ago and was again recently inspired by our friend Matt Klara's (fellow steelhead dirtbag) muddler.
I have a feeling the tube muddler will be this winters steelhead fly.
Wikipedia photo
The Muddler, was a fly popularized by fisherman and fly tier Dan Bailey.
One of the first Muddlers popularized was the Muddler Minnow created by Don Gapen of Anoka, Minnesota in 1937, to imitate the slimy sculpin. Gapen developed this fly to catch brook trout in Ontario, Canada. Read more about the Muddler at (Wikipedia).