Shipmans.
I've probably caught more fish on this dry than any other fly, all over the world, on both stillwaters and rivers. In fact even on streams where I've been fishing 16's and 18's I've caught fish on a size 12 Shipman's. And this is the colour. And this is the size. An amazing fly. It's pretty good when pulled under too and just sort of left to its own devices, but best of all fish it right in the film. I've used foam "breathers" but I don't like them; they're fine for twitching or in a wave, but for all-out fish catching tie it like this. I suppose it imitates the shuck... whatever, it works.
Tying instructions:
size 12, brown or olive thread, brick seal, pearl lurex rib, white poly yarn breathers tied along the shank.