Oh, I can so sympathize with you. I took a FMQ class at the LQS last week. We spent about four hours learning. The teacher had a hand out for the class in which tips number 1,3,5,7,9 and 11 say practice. I suggest making a 20 or so inches muslin sandwich, and practice any chance you get. I noticed that my last quilting stitches showed some improvements over the first, mind you not good enough for a real quilt, but definitely a move forward there. I think stippling would be easier than circles and flowers. The teacher gave us a good exercise that I though helped, she asked us to draw our design on a paper with a pencil. I was having hard time drawing the puzzles, she said until I can draw it easily, I won't be able to quilt it. Makes sense.
Finally, I would use invisible thread, it hides many of the imperfections. I even use it when I do straight lines because I am not that good.
OK, I need to go play with my muslin sandwich.
Good luck :)