Yup: you're right. There's constantly stuff that needs to be done. My kids are between 4-11. So we're out of diapers and potty training (which is huge).
I just keep finding spaces where I can create: early mornings, late at night, or during my lunch hour.
I answered this below, but basically every weekday between 5:30pm-8:30pm is family time (dinner, chores, bedtime routine). After that, I might try to build something if I have energy. Otherwise, I try to go to sleep. Weekends: wake up early and work on projects in the morning. Rest of the day is usually family activities.
None of this is perfect. I definitely don't have a perfect routine, and I definitely have that "hard life stuff" too: http://justinjackson.ca/real-life/
Edit: I should mention that I get a lot of work done in "fits of inspiration." Meaning: if I can't sleep, and it's 1am I'll work until 4am if I'm energized.