Living With Significant Other While WFH

I work as a music producer mostly from my home studio which is a converted bedroom in my (small) house. My girlfriend whom I live with is understanding of my sometimes crazy and unpredictable schedule. While I love living with her, sometimes I think back to when I lived alone, I could guilt-free drop what I was doing one evening, go into the studio and put in a few hours of work. Now with a girlfriend living with me, it's very easy to just relax with her and a movie. Does anyone have any tips for balancing life with a significant other and a crazy freelancer's schedule?