How do other people handle the "in moderation" part of technology? Especially for kids not yet in school?
My three kids are older (13+ now), and so we've given up here. We can talk to them about things, as dJackson mentioned, and we try to install values, but we can't control what they see, especially with cell phones.
Early on, since we had extra devices (laptops, then phones), we'd let them use them, but with us. They'd gain experience, they'd figure things out, but we were there. We also only let them use devices in public places in the house (living room/kitchen). That worked well, though as they grew through 10-11, it becomes harder.
We held off on cell phones until they were in a position where they weren't with us and we wanted to communicate. That typically was middle school when they entered sports/theater, and we wanted them to let us know about pickups or locations.
I think you have to experiment a bit. See what others do, understand that their experiences are based on different values, and different kids. Take what you find interesting, see what works, understand you'll make some mistakes, and share what works with others.