Every time I have a photo reference for my commission my goal is to get the artwork resemble the original picture as much as possible. With this particular commission the client wanted to be painted into "my world". Thus I made the face according to the reference photo and then changed the background and surroundings of the lady. In the photo the shadows on her face were a lot darker together with the background. In the painting however I had to change the tone of the shades to adjust the light so that it wouldn't look too weird.
I think I adjusted the shading/coloring of her skin what felt like 50 times. Every time I though I was finished, I found something to fix. At the end the paper almost had too much and I could feel its surface warning me that if I keep on doing what I'm doing I'll have to start painting on a new paper. And so I decided to let the paper rest and be finally satisfied with the result.
I often keep fixing things on my artworks that I'm 100 % sure I'm the only person noticing. Nobody would even see the difference unless I clearly pointed it out (and sometimes when I have the response is like "it would've been fine either way" but not to me). I always tell myself the most important thing is that I myself like the painting. That's why I'll keep fixing whatever I need to fix until I'm satisfied. I believe that's one of the main reasons I'm constantly improving: I never stop looking if I could do something better.