PS the only time I made golf covers over 20 years ago I used black acrylic knee socks in a lovely thick pattern and textured design. Just cut away and I believe I would be able to use the leg as the tube you start with here and just cut out the small throw away rectangle and end up with a lovely shaft cover that sews right into this pattern if yuo choose this contoured style.
You could definitely play around with techniques for sewing with this design and customize your own approach. Beginning sewers are just a project or two short of experienced. One of the reasons I love to sew is it is so forgiving and so remarkable easy to change everything as you go a long or make adjustments the next time. I rarely use a pattern. I have never learned to knit and crochet in part because I never took the time to learn the basics that would allow me to change patterns and designs as I go along. With sewing for some reason for some of us these changes come oh so naturally. I can tell from your suggestions you are already there. So make one or two or a set of these and all your future sets will be far more easier and fun and customized to your understanding how to make things happen. Happy sewing and golfing this 2024.