What would be your "Unwritten rule" of your Fallout 4 playthrough?

I've seen a lot of "Why is this?" and "What happened here?" posts and a lot of them are of a similar nature. The new player experiencing one of the "Unwritten rules" seasoned players suffered.

What are some of your Universal "Unwritten rules" that you use in your games? Or something you always do in almost every game.

for example: Contributing to the "Untimely demise" of Parker Quinn... OR... How you "greet" Kellogg at your "first meeting"..