First, this is by no means the definitive way to tie on a wing, but its what works for me.
I just started from the throat hackle, so you have to imagine there is a body tail etc behind all this.
This one is tied on an eyed hook, so i left a little extra space so as not to crowd the eye. It is size 1 old mustad limerick.
Couple of the picture are blurry, but you'll get the general idea.
1. You must have a level surface on which to mount the wing. I mount mine over the the throat hackle after tying the fibers down.
Tie on your throat hackle.
2. wind it full
3. Separate the fibers at the top and distribute them evenly on both sides, then wind your tying thread back about 2-3mm with 4 or 5 tight wraps, your hackles should all be at or below the plane of the hook shank. Make sure the area is level, because if there is a bump it will throw your wing vertical.
Use extra thread wraps to make it level. You will tie your wing in a the wrap FURTHEST from the eye of the hook, and the wing will not be tied down beyond the hackle a the front.
4. make your wing. Here i used 27 slips, 9 of each color. Usually the max i will use is 30-33, depending on wing depth, whether or not there is an underwing, and whether i'm marrying different fibers together. These are all goose shoulder, if you use amherst, golden pheasant, turkey etc, those fibers are thicker, so you will want to use less. Typically i aim for a wing that is just about the width of the hook gap.
5. hold the wing in your tying hand and find the tie in point. Here it is just a bit beyond the bend of the hook. if there was a tail, i'd make sure it fit with the tail length and height, but generally, just a shade over the bend of the hook is a good starting point.
6. Once you've found the tie in point, switch hands by bumping your thumbs and fingers from opposite hands together to get the tie in point, then make a 90 degree bend in the wing by stroking the fibers down with your right hand.
7. reassess the tie in point
8. switch hands again maintaining the 90 degree bend (hidden behind my thumb). at this point i wet the fibers to help them collapse, spit or water, your choice. Notice the gap between the hook shank and the wing!! that is important.
9. Now for the wrapping. make a death grip on your wing. You wont crush it. Dont worry. The death grip is important for keeping the wing shape and to prevent it rolling or breaking apart
Your thread should be hanging down the far side of the hook shank. Bring it under the hook, up and over the wing, then rather than go under the hook shank, go under the wing, through the gap between the wing and the hook above the hook shank, using the pinch wrap so the there is no tension on the fibers. Repeat this pinch wrap over the wing, under the wing through the gap, and back down the other side. Thread should now be on the far side of the shank.
Still maintaining the death grip with your left hand, hold the butts in your right hand and slowly and gently loosen the pinch wraps allowing the weight of the bobbin to collapse the fibers. The left hand should not move up and down, only the right hand and the butt fibers should move slightly inwards towards the wing. These are the ends you want to move, otherwise, if the wing moves, it will be shorter and misshapen - the death grip prevents this!