I guess we all dream of that monster brown trout on a fly rod. I certainly have...and I have caught many well over 20". Now I dream of a 30" brown. Streamer fishing is certainly a good way to make the dream come true. Most trout of any size will eat a streamer if it properly imitates a baitfish, leech or any other critter that swims. This also holds true for most species like bass, pike and virtually all saltwater species.
I often use a streamer as a "searching" fly when the water is high and/or a little off color and when on unfamiliar water where I see no other activity or feeding fish. I have grown to like streamers that are weighted at the head as opposed to weight distributed along the body. I believe that the weighted head gives life to some streamers especially between strips as the head of the fly will drop providing additional movement. I think this is especially true with leech patterns like the wooly bugger.
In my experience, brown trout seem more attracted to a streamer than are rainbows. I think they are just more aggressive. I am personally a little hesitant to say, as many do, "bigger fly (streamer) equals bigger fish". My experiences also tell me that streamers are more effective on dark cloudy days or after dusk and into the dark. Regardless, no fly fisher should be without a few good streamer patterns. A few of my favorites are shown below...
Wooly Bugger - I have always thought a wooly bugger best imitated a leech than a baitfish. I know others will disagree...regardless, they work. It is my favorite in lakes and slow water situations. I am most fond of olive and black and black and yellow.
Olive Woolly Bugger - by tightlinevideo
Muddler Minnow - this pattern is a real classic among streamers and, over the years hundreds of variations have been tied. This is a fly that I believe should be weighted evenly along the body as I fish it deep and close to the bottom where the weighted head provides no significant benefit with respect to fly movement. For those of you that do not know, the tier in this video is Bob Jacklin, a real fly fishing legend especially on the West Yellowstone and Montana area. The fly he is tying here is based on the original fly...as in the very first ever tied by the originator of the Meddler Minnow Don Gapen in 1936.
Black Leech - this is a fly I always have in my streamer box. I have it in black, purple, dark brown and a few of these have traces of yellow or red in them. If you have ever watched a leech swimming, this fly when fished with fairly short strips and a short pause is a very good imitation. Also, not shown here, I like a bunny leech in the same basic colors. In my opinion, these leech patterns are best fished in lakes and calmer waters with a sinking or intermediate line and a relatively slow strip and retrieve...leeches are slow swimmers.
Clouser Minnow - No serious discussion on streamers would be complete without mentioning the Clouser Minnow. This and a few variations are my goto flies in the saltwater. I also like smaller sizes for trout and bass. I think my personal favorite has a blue or combination bluegreen upper body that transitions into the lower white or light grey lower body. I tend to add a little flash (sparsely) in the mid section of the body. I tend to fish these with a longer and faster strip than most streamers I fish. This fly is effective just about anywhere for any species.
Tying the Clouser Minnow - by Bob Clouser