For me, it's shutting out work correspondence right at 5pm. Working from home most of the time. If some life circumstance vaguely demands my time in a way that conflicts with work, the life circumstance will win.

It's not horribly absolute. I did connect when I got a request to help some customers in Ukraine, figuring the very least I could do was help them out. Another customer that generally represents 30-40 million a year of revenue needed help off hours in December, and I obliged. In the event of a genuine emergency I'll be flexible (but in a hurry to get it over with, even if it means "slap flex tape on it and it should hold things over" sort of approach).

Keep in mind this is grading on a curve. A close colleague works in person at the office 6 or 7 days a week, generally for 9 or 10 hours, and on top of that spends much of his home time remotely working on things too. He complains that if not everyone matches his work ethic that we won't hit "the schedule", and I respond if that's the case, then there's a problem with "the schedule", not with people failing to work enough. Eternally poor planning with arbitrarily declared deadlines are not a legitimate source of emergency, and I won't play along with that.