The closest thing to a secret fly is that some of the ones i use have no names. Recipes are only suggestions if you ask me. I'll tie flies from whatever I have available. However, if someone asks me what i am using, I'll try to explain them, or if in person I'll just show one. that is, if it isn't too ugly. then again, sometimes the most effective flies are the ones that are all beat up. I once caught over 100 pan fish on a hopper imitation. By the time i was done, it looked more like a green weenie and it didn't float at all. ... but i never had to change flies.
This reminds me. I bought a batch of ringneck pheasant chicks a few weeks ago at a livestock auction. I wasn't thinking fly tying matrial because i have lots of pheasant feathers. I was going to raise them and let them go (maybe eat a few). They are cool to have around, and i also bought a couple dozen quail for the same reason. Plus, I have a couple bird dogs and they will give them something to point at other than chickens, and the cat. However when I got home I found that a few of them may actually be Lady Amherst Pheasants according to the box. I hope so, but I really can't tell yet. The pheasants all look pretty much alike at this age, but a few do look a little different and aren't growing as fast, so they might be. Looks like I may end up with some expensive fly tying material for about a buck or a buck and a half a piece!!! That is if they survive and at least one is a male. I once used a small lady amherst fly on a brook trout stream, and it was killing them. I heard it is an atlantic salmon fly, but apparently the brook trout didn't read any of the books either.