I had severe tremors (among other severe things) on lithium. I eventually lost most of my fine motor skills. I could not even put a cigarette to my mouth without concentrating really hard, had to give up eyeliner, force my brother to tweeze my brows and paint my nails.
I could not even button a shirt or write for shyt.

It was a very gradual decline for me though, they started out mild, and I waited to see if they would disappear, but then they morphed into the horror I described above...
My pdoc offered me propranolol for the tremors, which is a beta blocker and apparantly very effective.
I however haven't used it as by that time I was fed up with all the horrific side effects and draw the line at meds for side effects.
So I flushed the whole happy lot after he refused to change my meds.
So can't comment on efficacy, even though he swore by it....

The reason I'm partaking in this thread is to voice the fact that more than 2 years later my nail painting skills are still not up to par as I still have a slight tremor that becomes more pronouced when exercising my fine motor skills.

I think these tremors are downplayed alot, (even by my own pdoc) made out to be normal when on psych meds.
Maybe its just because of my severe and long lasting symptoms, but I think it's an injustice to pretend that they're no big deal, when that's clearly not always the case. Or maybe I'm just blowing smoke out my a.s.s and tremors are really no big deal in the grander scheme of things. Maybe I should of been ok with shaking like a fool...

On a more positive note, I have noticed that the more I practice, the easier it becomes.
I even managed (with only minimal mess) to paint my nails 2 shades each again, not too long ago.
So maybe part of the solution is to keep at all the things your hands struggle to do.