Practicing free motion stitching really does take practice. When I was complaining once, at a quilting group, about my challenges with learning free motion stitching, my colleague gave me a good hint, which was to find a print fabric with medium to large motifs and practice going around the shapes. I actually never did that but I did practice on several padded white rectangles of cloth that were required for a course in free motion stitching. Not all were used in class but they were there ready to go and therefore before I started any free motion on a project, I would practice on those white squares.
Last month, I was cleaning out some drawers and there were 3 of them totally filled with stitching. They had been sitting there for years so I decided to finally get rid of them. As they were all cotton I threw them in my husband's rag bag. He absolutely loves them and I have seen them in use on his bench in his shop and last week when he was doing a tiling project, this is what I saw in the bathroom.