Also, consider this: Step back from the stream with very light feet, as though trying to sneak up on a deer lying down in the rhododendron. And sit down, or stand still behind a tree, and wait.
The stockies are fish that have been behavior-selected and bred based on the ability to adapt to raceways.
The initial trout the state tried to breed were wild fish. It was unsuccessful. Wild trout need to hide in the shadows. Wild trout won't stay put if they can "feel" the walking of a human, the shadow of a bird in flight, etc.
Already domesticated selectively bred rainbow trout were purchased and brought into Pennsylvania for stocking.
Sucker spawn is always a good fly for these.
As long as the weighting of the fly is good, the leader is built right, and the cast is made and fished in a tuck-cast style. The stockies should be catchable.
There is one major consideration that I have come across as being much more significant than I previously considered.
SMELL!
The smell of your flies and line.
Not kidding.
Be careful when you apply different materials to yourself - hands, sleeves, vest - and what you use to protect your fly tying materials.
I have witnessed multiple species approach the same fly, one after another - almost like a line of customers - and get ridiculously close and then reject.
It was chemical rejection.
I am contemplating using goldfish as a canary in the mine so as to determine which insecticides and other wipe on or spray on materials are repugnant to fish.
I am now convinced that it is a VERY important concern!
(As with many things, the smells are what sells!)