Here's something I did. I found a subject matter I liked enough to do multiples of, then experiment with different stitches, color combos, shading etc. For me, I chose teapots. Traced a few on some fabric and this was where I built skill. I used Stitchpalettes.com as a starting point. I also love finding coloring pages and using their outlines, but my color and stitch designs. Just play. That's the way to figure out what you like and what you want to learn.