1st Thing You Do, When You Arrive At Your Destination....
1st thing you do, when you arrive at your destination, is sit-down, and watch the water surface, for about a half hour, from a position that you can fully view the pool or section of water you are going to fish. As Al Campbell told me when he spent 3 days guiding me to catch my first trout at the 1999 Fish-In , "Let the Pretty Girls Show You Where They Are!"
Look for sub-surface structure, submerged rocks along the floor of the stream, bends in the stream that have dug-out cavities along the outside bend in the stream where fish can hide. Depending on the coloration of the water and the color of the stream bed, trout can be hard to detect. Most of the time they rest near the stream bottom, conserving their energy, facing upstream waiting for food to drift to them. The trouts coloration is in most cases perfect camouflage to the angler. It is only with their movement by something that spooked them, do you catch a glimpse of them darting through the water.
Any shadow that passes over the water, can cause the trout to scatter to their Hidy-holes (they always have one to dart to for protection. So avoid casting your shadow on the water surf when fishing.
The trout can be feeding off of the steam bed if larva or pupa's have be disturbed from their protection on the stream bead, or they can be feeding on pupa transforming into nymph in the water column of the stream, they can be feeding on nymphs as they attempt their journey to the surface. All of these are surface attacks. If the nymphs (emergers) are still below the surface of the stream, all you may see is a slight bulge in the water surface betraying their bodies movement.
In every hatch there are always cripples, nymphs that get stuck as they attempt to shuck their nymph body. Again look for bumps in the water, betraying the trouts activity!
Recognize the areas on the stream that are prime locations for fish to place themselves. Rate the locations from best to worst. The best spot will have the larger trout!
There are many articles on FAOL, dealing with stream-side tactics, and how to recognize all the honey hole spots where you will find trout. ~Parnelli