Simple, but very effective. Tie in dark moose half way down the hook to the bend. Dub the butt end with black dubbing, then pull the moose over for the back. A few turns of blue dun (optionally brown) hackle, then black dub for the head (this one didn't come to the eye as close as it should). I've caught fish on this on top, partially submerged, and fully submerged.
NOTE: I will usually clip the hackle flat on the bottom to get it to ride lower in the water and sit straight.