I find tying a small version of Al Campbell's shrimpf in red and black with a little flash works well enough as a crawfish imitator in my dingy central Lousiana lakes. It's a quick and easy tie and I think the fish interpret it either to be a small minnow or a crawfish. I also like that the body and winging material is very flexible based on what I have. I can use yarn, chenille, dubbing, antron, or whatever I have on hand for the body and bucktail pieces, squirrel, craft fur, or kip's tail for the wing to customize the fly to mimic local colorations of crawfish and/or minnows. Do a search for "shrimpf" on FAOL and you'll find the pattern.

Kevin Smith
Central Louisiana