I started by buying up a bunch of old fabrics cheap at a Salvation Army Store. Think the whole box cost me $5. Then I started with the largest prints, and worked on quilting around those. As I improved, I worked my way slowly down to outlining the smallest prints. There were hearts to practice on, and plaids where I could do geometric work, solids for "fill in quilting", and vines to follow and outline. I ended up buying more cheap, used fabric and continued on. It saved me! Prior to that, I couldn't FMQ for the life of me, and I was getting frustrated with the tutorials, etc. I had to practice, practice, practice moving that material around, really getting the feel of it. Eventually I graduated to "sandwiched" pieces, and then to quilts. Yes, it was a long process, but it was what I needed to do for me to learn. It was even harder because I have peripheral neuropathy in my hands (numbness and tingling) and the fabric had a different feel to me than it might for other people. But now, I am praised for my quilting abilities.
I also very, very much like Leah Day's suggestion of putting a serpentine line of quilting on a quilt, and then meadering back and forth over it. I just love her!