What is the actual goal here? Make more money? Spend less time working? Save humanity?
During my diverse career, I was cumulatively very productive, but it came in bursts. In my case, at least, trying to be continuously productive would have led to early burnout. My secret was to have many things going on and put my full effort into what attracted my interest in that moment. Sometimes it was something I was compelled to do, like attend to the emergency case presented to my veterinary hospital. Other times it was something I was inspired to do, like design a workshop to help colleagues in my animal health company overcome some obstacle. Or maybe spend hours on a spread sheet for a simulation model to help veterinarians better understand some disease-treatment interaction. And sometimes I just went for a long walk to clear my head. Yes, I consider myself fortunate to have been able to work this way. I could never have sat in a cubicle all day writing code or something.