Most of my woodworking tools have been shipped to my grandson and I have been showing him how to use them. I kept enough tools to do maintenance and small projects.my shaking limits the fine stuff and a lot of sanding covers some of the mistakes. but I am not pleased with my work now.
I started to build two shadow boxes to display some tools and found out that what used to be easy is now tough. bob w.
Bob, I'm glad you have a grandson to receive the tools you've taught him to use. That's a very good thing. On the other hand, I myself would hate to give up working with wood. For your example, a pair of "board buddies" (I hate the name!) would cure the problem of routing grooves, and not a few other kinds of cuts or functions. They'll do the job of holding where you want in place while the cut is being made.
There's a whole world of "accommodations" out there as we've tried to get people to work despite apparent problems. People like my cousin are born with cerebral palsy deal with things like this all their lives (my cousin graduated from MIT, Summa cum Laude). My wife, a nurse, is going to see what she might be able to find.
I don't know what your precise position is at the moment -- doctors, healthcare and the like -- but there are medications for tremors, too. Maybe you know them all, and maybe you've tried them (cogentin is one I'm familiar with. "Benztropine mesylate is used to treat the symptoms of Parkinson's disease and tremors caused by other medical problems or drugs." )
My wife and I will see what more we can find.