This is a very effective streamer pattern for many species.
Hook: Mustad 7957B (wet fly 4XL) 10 - 2
Tail: maroon hackle fibers
Body: light gray rabbit fur
Wing: turquoise (dyed) saddle hackle
Throat: red hackle fibers
Thread: black monocord
This streamer is stubby by most standards, but for some reason, it makes it more efficient. Ask the fish why. I'm not exactly sure myself. This is a plain old streamer. Full foundation, tail, dubbing, throat, hackle, finish with a wrap know and cement. If you need further instructions, buy a basic fly tying book or check the archive. I see no sense in being redundant on this fly because it's so basic.
Part of this fly's appeal is the color sheme. It's best used on days when the skies are blue, maybe not bluebird day, but at least some fair portion of sky showing through the clouds. The turquoise color is a good mimic of a green being colored blue by the sky as seen from below. One variation possible is a more purplish tail, but the idea is to give the impression of a bruise, in contrast to the scarlet red of the throat representing the gills. This color diferentiation really alligns the fish to strike the fly at the proper angle from behind, assuring better hook ups on the strike. Don't use scarlet on both ends.
Fish this streamer as you would any standard streamer, with a swimming motion in still water, or playing downstream, swaying it across the rod's arc (l to r) while slowly giving ground in moving water. Just be ready for strikes from below. They're likely to be rather splashy.