I always take a multi-tool, and husband makes fun of me for doing that, until he tries to borrow it ...! I have a bit of thing for multi-tools, mine looks like a bug, I call it my Transformer.
Other than that, I don't take anything other than as little as possible, because mostly, anything you need can be bought where you are. I know this for a fact because our luggage was lost on a 3 week trip to Canada and the US and was returned to us the day before we left. I made do on that trip with a few outfits hurriedly purchased from Costco!
I've got a SIL who lives in the US who drives us all mad because whenever she arrives for a visit, she brings more luggage than I have ever seen for just one person, she carries her own pillow and duvet and goodness know what else. She has been known to ask people to come to the airport with 2 cars! I kid you not. (She does also bring golf clubs).