If you're in a canoe, drop anchor well above the area you want to fish. Let out slack rope until the current brings you within range of the fish. Make initial casts count. The longer you spend working an area, the less chance of attracting the vermiculated czar of the pool. Any fish grows suspicious after watching a few comrades get hoisted out of the water.
Big specks close their mouths and roll their eyes at the repeated casts of hovering anglers.
Once hits dry up, move on to a fresh area. Presentation is crucial. Putting an offering in front of trout in a graceful, natural manner means utilizing all variables to advantage. Where to cast, retrieval speed, and lure weight to use depend on water depth, current speed, and where trout are holding. Current is a trout stream's dominant force.