Europea 12

E:12 is one of the most well-known dry flies and imitates an adult Caddisfly. Sometimes, you can think that this fly is all you need when the fish are biting. I myself hook a lot of Rainbows each year with this good fly. Land well and long leader line along with fly dressing to hand as it should be dry for fishing, and it's usually the first cast that gives a catch when the river is at its driest. I think powder is the absolute best for this.