Is your frame level at both ends and in the middle going both directions? I was taught to keep your eyes focused ahead of where the needle is stitching. I keep mine an inch or even 2 inches ahead depending on how close the pattern is. Also, don't grip the handles hard. Lightly hold them. Sometimes I use only thumb and first finger. And of course, relax. In my class, the teacher brought in bottles of wine for everyone to sip in the afternoon when we were getting tense about finishing on time. What a help that was!
With a pantograph, you do not see on the quilt where your pattern lines were, just the outcome and that helps alot. Starting with gentle curves as someone mentioned before is good. And stitch regulation at first.
Draw lines across your practice quilt 2 or 3 inches apart. Then practice cursive c's and capital s's across over and over again. Keep them within the lines, but filling the space. Then try printing u's with 90 degree corners all the way across.
It does take a long time, but you will be so happy when you see improvement. I was.