One thing I value above all else that has not been mentioned is a magnetic grocery list tablet and pen that STAYS IN CAMPER. You will constantly find things that need a little repair or upgrade and things that you always forget to bring or things that you brought that end up being in the way.
The tablet allows me to make a list of To Do items before the next trip. Whether it is something simple like packing extra batteries for something you forgot or like me I have decided that in my bunkhouse the little closet needs more shelves for dividing the kids' clothes. You will always have notes on nearly every trip your first couple years.
Aside from that the best advice has already been given, a sense of humor. After all a camping trip should be a vacation not a chore.