I know...the answer must be practice practice and practice. But do you have any specific drill to reduce shaky hand? I find that writing in good posture and comfortable arm position might help. And how I hate when I am doing a piece for a gift, I am sooo nervous and made silly wobbly lines. But when I am on a casually practice, my upstroke is perfect (OK, not perfect, neaaarly perfect). Gah!! Do you think writing faster will make it better? Because I see so many people could write in a snail tempo, but amazingly steady. Hm...?!
sometimes I try and trick myself and think "this is just for practice"! sounds silly but often times it works. I still get nervous at times and it shows. I always say
whatever you're feeling flows from your pen.
classical music, yoga breathing and sometimes only a glass of wine helps! it will get better, with practice comes confidence and THAT is what you will see on paper.