Julie and I have a funny connection to the movie Cocktail. In it, one of the main characters always has what he calls “Coughlin’s Law”.
Things like “anything else is always something better” and “never show surprise, never lose your cool.”
If I had to come up with one for myself I’d go with “Many things can be accomplished with duct tape, WD-40, and a sledge hammer”.
My grandfather would have added “and a couple of half hitches.”