Hi Bobby.....you've asked a great question and have gotten alot of good advice. One thing I can add is the importance of tail "splay". I shoot for at least a hook gape splay on my drys. It's easy to do by making a small thread ball and tying down the fibers aginst it. This makes the tail act as a little outrigger to keep the fly upright. I also adds a parachute affect as the fly settles to the water during the cast.
Good luck!.......Jason