I have problems with my hand writing too. I almost always print in capitals as any thing else I try is usually unreadable! I can manage short 'post it' notes to myself and use them to 'jog' my memory. If I have a form to fill in, I try to get an editable .pdf version from online so I can type in the answers then print the form and if there is no online version, I get someone else to fill in the form for me!
I have sand filled wrist weights that do help if my hands / arms a shaking when trying to write (as they often and mostly do) but they are a bit awkward to carry around so I keep them on my desk and only use them at home. If I need to sign something or do (short) writing while out and about, I usually have to steady my writing hand by clasping the wrist of that hand with my other hand.
Though I have never been truly ambidextrous, there was a time that I could write really well with my right hand and reasonably well with my left. I even had a bit of a 'party trick' where I would write backwards! Now, I cannot so much as scribble with my left hand, my right hand produces writing that is worse than when I was a child learning how to write and is barely legible. The 'party trick' is definately no more.
Having use of computers is a real help as I can still type my communications. My typing speed has changed from a recorded typerate of 25wpm (I got a certificate for it) and unrecorded 50wpm plus to 25 words - eventually! I make lots of mistakes typing too - especially when my brain clearly registers a particular key press but my fingers seem to take on a mind of there own. Also, I cannot type for long due to getting pain in my hands, arms and shoulders and have to take breaks - I also have very bad lower back pain and sitting typing for a while only makes that worse.
I know my motor skills are affected - my neurologist has observed and noted this. On a practical note regarding motor skills; I used to eleviate bordom with a hobby of papercrafting that included some origami but was mainly model making where I would design a model on the computer (rarely) or download a model, print out the model, cut the various model shapes out then shape and paste the parts togehter. As can be imagined, such models required much coordination and use of fine motor skill. Sadly, due to the problems with my hands, I rarely even attempt such papercraft now and when I do, I can very easily get frustrated with the fine(r) work required and feel like just giving up because of the various pains I get sitting for a while.
I have not totally given up on writing (or papercraft), I have just had to re-evaluate my capabilities and adjust accordingly. I usually stay positive about my abilities too and stick to the idea (some might say mantra others might say cliché) that "It's not what I cannot do but what I can do that matters".
Edited to correct mistakes an put in things I missed out!