Pretty simple really. Instead of trying to control how I spend your time, I try to take advantage of whatever time I have to do what I'm feeling like doing. A key part of this is reducing the amount of bullshit and setup time necessary to do the things I want, and combining activities.
For example, I try to practice guitar 4 hours a day. I also like watching TV. So, I have a little practice amp in my living room that's always plugged in and has a cable so I can just grab a guitar, and noodle while I watch TV. That alone gives me about 2 hours of practicing mindless stuff.