What's a rule that you follow that has improved your personal life?

I've designated one room in my house to be an Airplane Mode room. Technically it has WiFi but whenever I'm in it I behave as if my phone didn't have any reception. Believe it or not, actively pretending that your phone has no WiFi works better than just passively putting on airplane mode. I always get a sense of calmness when I enter.

What artificial limits do you impose on yourself that ultimately enrich your life?