When I lived in BWO country I made two different style wings. One way was to peel the fibers off of a pair of blue dunn feathers until I had two neat miniature feathers. Actually when you do this you end up with just the tips of the feathers and you may have to try a few times until you select the right 2 feathers to start with. Once you have peeled away enough fibers to give you the right size wings you then mount them with the convex side facing one another. I mount them by holding them strait out over the eye of the hook and put three very light loops of tying thread around the. The loose loops don't kink the little stems and this allows you to let your thread bobbin hang and to release your grasp on the little wings. At this point you can see if they have stayed on top of the hook shank or if they have rolled to one side, split apart etc. If they have went wrong for you, just loosen the thread and try again, and again, until you are ready to scream
Really, this can get frustrating but trust me you will catch on. Once you have them staying on top and sticking strait out over the eye just gently pull them up & back so that they are toward the tail and make a few tight wraps against the base of the little quills. When you let go they should stand strait up. If you get to this point you are almost home; take the dubbing needle / bodkin, and stick it between the wings and separate them, now with your free hand (you'll figure out that you should come in from behind with the needle) with the free hand take the tying thread between the wings at the base and do a cross wrap. By this I mean a crisscross wrap between the wings. You will see how you must wrap and how much tension to use here. The idea is to make them stand up & apart at the angle you would like. Once you have them in the position you want place a tiny (and I mean tiny) drop of lacquer cement at the base of the wings and on the thread that secures them. Take a rest while you pluck a hackle for the collaring and let that glue set up. Then hackle the fly and finish the head. Remember don't work so close to the eye that the head and cement cover the eye.
This takes practice and you will be doing yourself a favor using a size 12 for your first try and make anything you want but if you use this technique and make some size 12 Adams using grizzly tips you will have some usable flies and get your training in before trying the BWO in 16 - 20.
The second style wing involves using slat gray mallard wing quill sections (my favorite wing) and believe me it is the same process but a little tougher to master so let's leave that alone for now.
PS. I'll see if I have some good examples of these wing styles and past them to this reply, if I do I'll PM to let you know they are here. There is a third way too, 'burning' and that's another story. I never did well fishing with burnt wing flies although the wings look very real. Funny thing here, the more real I made dry flies and nymphs look the fewer fish those patterns caught. Sounds weird I know but that's how the order of things worked out for me.