Elder46,
As far as trembling hands and fly tying goes, all I can tell is that you just have to keep at it and learn to compensate.
I still fight with it, but through practice you can learn to work with it. Remember that it's not how it gets accomplished, but that it gets accomplished.
Some little tips:
Learn to rest your hand on the vise as you apply materials. Having the heel of your left hand rest on the vise while you position materials on the hook helps steady your hand.
Use tools to pick up and place materials. Picking up feathers or small parts/pieces is often easier with a pair of pliers/tweezers than with your bare hands. Larger tools are easier to handle than smaller ones for most of us with shakey hands. Sometimes you have to modify tools, grind down points to get them small enough, bend things, put padding on jaws so you don't damage materials, stuff like that.
Make sure you have a comfortable seat at the right height. A properly fitted chair can reduce stress on your muscles, which is one major cause of the shakes. If your upper body is in an unnatural position, your hands are more likely to be unsteady.
Innovate. Don't be afraid to do things 'differently' to accomodate your body or your mind. You don't have to tie like everyone else. If you are more comfortable wrapping in a different direction, holding materials differently, or applying them in a different order or manner, then do so. It's the end result that matters, not how you get there.
Learn to recognize when you are having a good day or a bad one. This happens to all of us. On a day when you are not doing so well, tie the easier stuff that doesn't require as much digital dexterity. On a good day, tackle your more difficult patterns.
Don't give up. Trembling hands are something that can be overcome with practice and patience.
Good Luck!
Buddy
It Just Doesn't Matter....