If I am fishing during the crayfish molt, I'm usually fishing Haddon's Dead Drift Crayfish. It is an effective fly. However it is a pain to tie, so I buy mine.
Using a multi-colored Woolly Bugger or some sort of variant is not a bad idea. In Ralph Cutter's book, Fish Food
, he mentions dead drifting buggers as an effective way to catch trout. A fly that he uses quite a bit is called the Goblin
. It is a Woolly Bugger variant.