When doing intricate piping, writing, I hold my breath. If I breath and pipe words or lines it's a mess.
Also only move your wrist, don't swing your whole arm. It doesn't need to be perfectly still, but try mostly moving your wrist. Sometimes I rest my elbow on a tin can.
That is what works for me. Also practice, practice.
I realized long ago that I would never be able to do all the pretty piping - - my hands just shake too much. It's not a neurological condition or anything, I just can't keep them steady. My dh made me a rest for my wrist that sits on top of a camera tripod. It helps, but I still don't pipe anymore than I absolutely have to. Luckily for me, there are so many beautiful designs that don't require piping.
I just took a class with a Food Network great Joshua John Russel (on Craftsy) and he has a unique way to stop his hands from shaking. He gets eye level with the area he's working on then steadies the bag by resting it against his cheek. Seriously. He agrees it looks silly but you should see how neat his work is. I rest my right elbow on the counter then steady the tip with my left hand.
Might not be at all but do you drink any caffeinated drinks within a few hours of decorating?
Coffee, tea, pop?
I was getting really frustrated with my shaky hands then someone who did murals on wall was talking at a party I was at and she mentioned how the murals could take 2-3 days for her and the worst part was she couldn't have coffee to keep her energy up because her hands would shake.
So I stopped drinking coffee on days I was decorating ....no shakes.
I know this might not be the issue but thought I would share my shaky hands fix
Thank you everyone for your suggestions. I'll try them and see what helps.
I had to stop drinking caffeine because of arthritis, but it helped my hands too! I also use my left hand up against the tip/bag to help steady if I need it. I definitely want to check out that craftsy site further. They have a lot of neat things on there! I don't do a lot of piping the writing unless I have to just because I don't like it. I LOVE cutter though!