Here are some other ways I have seen other people ( but not me! ) do things wrong:
1: they have camped under the wrong tree when snow decided to break a branch off which then ripped a hole through their tarp in the middle of a snow storm. Only happened to that one person out of 20 ( but 3 men to a tarp ) and only on that one night out of 30. And only dumped snow all night on one person out of 3 under the tarp. But that night it s**ked to be him! Pick trees with branches that won't break off!
2: Don't allow your still pretty new factory taped tarp to spring a leak at the RL seam during an all night down pour. But result was not too bad, because it was not cold weather.
3: Don't sweat ( apparently without realizing it ) or put out tons of insensible perspiration ( vapor ) which proceeds to condense in your down over a week period, while also choosing a week of cloudy/foggy/rainy days with no sun for drying.

So far in my many years of tramping through the woods I have not made any of those mistakes, and I suggest Y'all avoid any of those things like the plague!