See: Goose Biot Prep for more info.

1. If you got this far, you should have no trouble finishing the prince nymph. Make sure the wing biots are the same length. Measure and cut to 3/4 hook shank length. Take one biot and hold against top of hook shank right behind eye of hook. Be sure the wing butt does not extend into eye. I wouldn't want a butt in my eye either. Make a loose thread wrap and tighten. Anchor with 4 or 5 more heavy wraps.
2. Do the same for the other wing biot. It may help to pin wing against the side of the hook shank with your thumb and let the thread torque pull wing up on top of shank.
3. Wing angle is a matter of personal preference and it is hard to get them both the same. It is like riding a bike, get right back up on it if you fail and keep on trying.
4. Should look like this.

Now ready to Whip Finish