Matt Sparrow, the man-quilter, says he practiced 10,000 hours on his longarm machine before hanging out his shingle. I might not live that long, but am learning the value of practice. For me, the best way is to use a panel. Then if I mess it up it is not a huge waste of time and money like it would be if using a pieced top... but it is also useful when finished, unlike using a big hunk of fabric with no plan for it other than scribbling stitches.
This is the current practice panel. I wanted to use contrasting thread because it is easy to see. However, it doesn't show up much on the lighter areas, so I did lots of texture stitching in those. This has helped with confidence to do the fancy quilting I want for Cobblestone Lane. I'm particularly happy with the zig-zag as I did that freehand. It has a few squiggles, but far less than the last time I tried it. One key: stop telling myself that I can't do this and just do it.