I live in Oregon now but fished for years in Colorado mountain creeks and streams. You're on the right track...90% of what a trout eats are sub-surface insects. Try flipping over some rocks and look at the little crawlies that call it home, you'll find that your PTs and Princes are where you need to be. Basic stonefly nymph patterns tied heavy in size 8, fished in deep holes will produce. These can be simple (merely suggestive).
The sub-surface list...
Wooly Bugger:
(big, small, light, bright, dark), this pattern has caught more trout in more conditions than any other pattern
Nymphs:
pheasant tails, prince nymph, stonefly nymphs all in sizes 4-16 (these will all cross over to dragon and damsel fly nymphs as well)
Larva:
caddis (google Mop Fly) with bright green body and black head, my buddy catches trout, salmon, steelhead, LM and SM bass and CATFISH...all on the same fly!!
Soft Hackles:
simple thread or floss body (ANY color), soft hackle feather, small thread dam or dubbing ball for a hackle prop
Quicky Stonefly Nymph pattern:
Hook: nymph or streamer hook sized to your local bugs (size 4-12 will cover most)
Thread: your 8/0 in black or brown
Bead: brass or black sized to the hook
Body: poly yarn (normal cheap yarn in black, brown, tan, or yellow) or dubbing of similar color
Rib: your copper wire is perfect
Legs: hackle in a similar color
Tails: 2-4 pheasant tail fibers or 2 rubber legs
1. Start by putting your bead on the hook and clamping hook in vise
2. Start your thread behind the bead and lay a thread base back to even with the barb
3. Tie in your tail material, forked horizontally
4. Tie in wire and yarn at the back of the hook with the wire and yarn along the shank up to the bead and advance thread forward with touching turns
5. While at the thorax area tie in a hackle behind the bead
6. Untwist your yarn and wrap tightly forward to form a body tapered from skinny at the rear to fatter at the front and secure with 2-3 thread wraps
7. Wrap your wire around the yarn body to suggest a segmented body and secure behind the bead
8. Wrap your hackle 3-5 times behind the bead (to suggest moving/wiggling legs) and secure
9. Whip finish and a touch of cement
This is a Brooks' Montana Stone I have a whole box of these in various sizes, colors, variations, etc. The pattern I described is a variant that has worked everywhere I fish... rivers, lakes, creeks, Colorado, Texas, Oregon, Wyoming, etc. I can be scaled up or down, colors changed, etc. to mimic local fare
With trout there are 2 games....#1 is matching the hatch (feed them a fly that closely mimics what they are eating) and #2 is blowing their minds (ex: fishing a big bushy dry fly in winter, streamer at mid-day, etc.). It's the old attractor vs. mimicry debate. My best advice is to get a few hatch charts for your area, see what's popping during a particular season and tie a couple versions of hatch matchers and some attractors in that realm as well. Independant reaearch has always served me well, I don't go to fly shops with questions...I go to the river for answers
If you want some dry fly guidance, I can help there too!
Post some of what you tie and we can help you sort it out
Tight lines!
Dutch
