This post is made for the sole purpose of showing Clif of Lunker Hunt how to tie a certain special Baetis pattern that is guaranteed to catch on the Bighorn river in MT. At least I have had good luck with it when the Baetis are coming off.
Ingredients you will need:
Nymph or emerger hooks size 16-20.
Black hackle (this could be substituted if you don't have it)
Grey or black dubbing
Turkey flats (could be substituted with just about any dark feather fibers)
Pheasant tail feathers (again, same as above)
Start with the hook. I have listed a Nymph or emerger hook, but didn't specify straight or curved. I have really only seen these tied on straight hooks but I don't know why. In the water, the bugs that this pattern mimics squirm around and definitely could be curved.
Tie black thread on the hook all the way back to the bend. At the start of the bend, tie in 3-6 black hackle fibers with the tapered ends sticking out the back an additional 1/2 - 3/4 of the length of the hook. If you don't have black or dark hackle, you could use a couple pheasant tail or other feather fibers. It's not that important, trust me; I asked a fish once. Ideally when you tie in the fibers they will fan out a little bit rather than being in one fat clump. You can tease them and play around with the way you tie them off to enhance this.
Now you're ready for the pheasant tail fibers that will serve as the legs. Try to get 6 fibers all tied on to the top of the fly, pointing forward. Getting the length right is the hardest thing with this fly. You will either end up with legs that are way too long or way too short the first 50 times you tie this, at least I did. You'll figure it out. See two photos down for an idea of what's about right.
Once you wrap around the pheasant tail fibers with your thread a few times you can trim the back ends off. Save them for later use on another fly or toss them, it's up to you. Next add a small amount of dubbing (I use black or gray). This gives some bulk to the thorax where the wings will come out of....if it were a real bug.
Next bend the pheasant tail fibers back, and split them so half go on each side of the fly. At the same time, pull the turkey flats forward, and when you do the Ptails should stay pointed out or back. This is the most frustrating part of tying this fly. Tie off the turkey flats. Next I always pull the turkey flats back again, tie them off again and then clip. This extra unnecessary step I hope helps keep the fly from falling apart if it gets poked at by a fish's teeth (hopefully) or the rocks of the river.
Whip finish and you're done. You can play around with the way the legs sit out. I usually do because I'm a bit of a perfectionist and like it to look pretty in my box, but once you fish it for a few minutes they're going to go where they want to anyway. This is what it should look like when you're done:
You could also add some very thin silver or copper wire to add segmentation on the lower body, but I have never done this or seen it done. The bugs themselves are of course segmented, but on the black of their body it's fairly hard to see, or at least the fish tell me so.