A cracked door taught me to never skip the edge inspection.
I was putting in a tempered glass door last week and rushed through the prep. I skipped checking the edges for small chips or cracks. When I set the door, a tiny chip I missed made the whole pane shatter. In my experience, this kind of thing happens when you try to save time. Now I always run my finger along every edge before setting the glass. This extra step has saved me from similar breaks on a few jobs since then. Your mileage may vary, but I hope this tip helps you avoid the same hassle.