I am right there with you. I have a muslin sandwich next to my machine, and I practice almost every time I sit on the machine for a couple of minutes, it DOES get better. I am now at the point where my stippling on small size quilts look OK. Can't for the life of me do it on bigger quilts, too unorganized and the quilt is heavy. But I did ask Santa for the FM slider to help the bigger quilt "slide" on your machine, so maybe this will help.
Also, a couple of things that helped me where reducing the motor speed to half, and then floor the pedal, this way the speed is constant, and I can just control moving the fabric.
We will get it one day:)