I set my stitch length to 0, because the speed you move at determines the size of the stitches. This way also the needle move quicker. I move my needle fast but my fabric slower, and even slower at the curves. You have to adjust the tension until the stitches look right and practice, practice, prctice. Prepare a few practicing sandwiches with solid colors. This way to get to see your stitches with no trouble.