Keep your arm loose and use the whole arm while drawing. That probably doesn't really help at all...

Can you post what you're working on? Maybe we can help more if we know what you're doing wrong.

Try to keep the motion fluid and smooth. Not too slow or you'll get jittery, but not so fast that you're inaccurate.

you can also practice connecting dots with straight lines to improve your coordination.
not sure if this will help
https://www.youtube.com/watch?v=Dia-GXgv1NM
But she gives a few different tips on drawing circles.

I'll take a look, thank you! x3

I do admit, I'm guilty of using the potato method often haha. Sometimes I can draw a circle perfectly from just drawing it. But if I really wanted a perfect circle, I'll just place a line shape in.

In the end, it's really in the practice and confidence of drawing the circle.

I use coins or a school compass. In pc I use a vector program.

my circle never ever look like a circle :c