After my first YouTube video about holding a handstand I got feedback about having an arch in my back, and after watching the video I was able to see it, especially near the end. Since then I decided to try changing my point of focus from looking at my hands to looking at what is behind me. It is much different and took a few months to get used to, but now my back is much straighter.
After watching this video I see that my feet are still not quite over my head but at least my back is straight, which feels better too. 🙂