While considering streamers, I'd also recommend picking up some barbell eyes {clouser eyes}. They come in a myriad of materials, from tungsten, to nickel, to lead, as well a variety of weights.
I tie them onto woolybuggers, as well I will use standard clouser style patterns tied with bucktail, not to mention a 1\2 &1\2 incorporating hackle for the tail.
Sized accordingly, they hold low in the column on the swing when currents are running heavy, they can get down in pools, and in the right size and colors behave very much akin to a darter.
A favorite technique of mine that I employ to cover alot of water and probe for aggressive fish, or to trigger strikes, is to quarter the cast upstream and mend to get it down as quickly as possible. Once it has made contact with the bottom, I'll throw a big parachute mend downstream, and strip as needed to make the fly swim broadside to the fish across the current. On the strip it rises in the column, on a tight line it holds the column, and on a loose semi-tight line it dives. By varying stripping technique, length, and speed, a multitude of looks can be imparted to the pattern. Not to mention, when swinging the pattern broadside with a belly in the line, when a fish takes, the energy is cushioned by the belly, so a lighter tippet may be used to get down and break offs are reduced.
I know a highly effective pattern to use on the Deleware when the alewives and blueback herring are migrating, is a white zonker tied upside down with a hole poked in the skin to push the hook point through, and clouser eyes at the head. Some very large fish fall to that pattern.
Very effective means of working the lower levels of the column.
Hope this is helpful.
Tightlines!!!
