Hot orange mini-muddler.
I don't use this very much, but when I do use it it works a treat. There's a one-week period in August when all the trout seem to do is follow the large muddler. It's overcast, there's a hell of a lot of fish running the slicks, it's not raining - although it is threatening.
Hot orange mini-muddler Grenadier on the bob (well greased), Soldier Palmer in the middle, Black Spider on the point. Fish really slowly, but do work the flies. Basically all the fish really want is something relatively small and just underneath.
Tying instructions:
size 10, brown thread, hot orange seal, orange palmered cock, gold wire/mono rib, muddler head with some fibres sticking backwards in an enticing manner (don't clip these ones; use your fingers for that just-got-out-of-bed effect that all men and fish love)