Caddis flies do not linger long at the surface. When the hatch is on, the bugs dry their wings and lift off to fly above the surface, well out of reach of hungry trout. The bugs are way more vulnerable as they make their way up through the water column. And trout know it. If the fish are not taking bugs on top, chances are they are feeding on emergers.
Start with a 9-foot leader, tapered to a 4X or 5X tippet. Cast across then roll an upstream mend, let the fly swing and watch for the line to move with the take of a fish.
Tie this fly with brown thread on a No. 14-18 Tiemco 2487 hook. Slide a black bead up the hook to the bend of the eye. Build the body with creamy orange dubbing and rib with fine copper wire. For the thorax, wrap a strand of peacock from the eye of the tail feather. Finish with a collar of Hungarian partridge.