My friends and I have what we used to call the secret weapon. We use it on the Hooch DH areas. Its a variation on the Royal Trude. Wet or Dry it was killer. Last year I don't think we caught the first trout on one.
The last couple of times I went, I messed around with a "spider" (for lack of a better term) made from a piece of foam strike indicator.
I fished a slow, over-fished stream in S. Kentucky and the big guys would only hit at this one. The little guys were striking at it every time I put it in the water. I got so tired of landing 3-4" fish that I started jerking it away before they hit.
90% of the time, I am nymphing, so my go to flies are fished at the bottom. I have mentioned my go to pics elsewhwere, but I will do it again. I do so with some hesitation though, as the purist angler may call me out as a bait fisherman, but what th heck. I am both a tyer and a student of entimology(even if I cant spell it), but very very often, my go to is an orange egg patern and a red SanJuan Worm on the drop. Particularly in the spring when bows spawn, and fall when the browns get to it. They also work well just about any time on stockers and giant high pressured fish alike. Part of the fun of fly fishing is making observations and choseing flies accordingly. Another part of the fun once you have a hatch or fly figured out, is seeing what of your crazy flies creations you can get them to bite. However, I feel like I can walk on any unknown water in the world, and hook up right away with these flies.
I will say though, that I have little confidence in the vast majority of these patterns that are sold in fly shops. The egg patterns are to big if not the wrong color, and the same goes for the SJWs. I tie the SJW with the finest red Ultra Cheneal on a tiemco 200R size 18. Never much more than 1" long. I make the orange or yellow eggs much smaller than what can generaly be found in the store.
Anyway these are the searching flies I generaly use when I first walk into new water. I will start tinkering with other flies after I have stuck a bunch and am all warmed up. In that time, I have had time to make some observations and make some changes.
Another strategy is often a big attractor stone followed by a midge, cadis larvae, or PT nymph.