The article linked below has the ingredients for a Holshclag Hackle Fly, a generalist crayfish pattern based on th wooly bugger. The pattern is shown on page 6 of the pdf. These were one of the Top 20 flies mentioned in Tim Holschlag's "Smallmouth Fly Fishing", which is an excellent book on the topic.

http://www.smallmouthflyangler.com/_...ek-article.pdf