These are more like tips than hacks....but hopefully useful.
Everyone on the camping trip should have their own flashlight or even two small ones.
And a whistle on a shoelace or in a secure pocket for safekeeping.
For young children have a card with identification and contact information on them in case they get lost. Be sure to tell them not to leave camp without an adult. And be sure to tell them that if they think they might be lost they should stop where they are and blow their whistle a few times.
Bring extra keys for whatever vehicle you came in.
Bring extra water in case water sources are not what you thought they would be.
If you need to purify water you might want to bring a bit of something to make it more palatable such as a bit of powdered flavoring.
Trekking poles are terrific. They help prevent knee pain and they can act as a crutch if needed.
Make sure someone back home knows where you are going.
Save some of those small hotel shampoos, etc. to bring camping.
If you are hiking very far get some double layer socks or wear two pair. Great to prevent blisthers.
For simple wound care bring super glue.
Bring duct tape. And some wet wipes in a zip lock bag. They are always useful.
Paper maps can be useful if you won't have cell coverage.
For car camping:
Bring a small portable vacuum to clean up your tent when needed and especially before packing it up.
Bring some first aid supplies.
I’ve just started the car camping thing, so I’m no expert, but some of the stuff I’ve noted for myself to put in the car: a set binoculars, a safety vest (to put on when I get on my bicycle), and an analog timepiece (aka “a watch” - one that doesn’t need to be recharged every night!)
On water supplies - it is sometimes difficult to cart lots of water with you; so if one is heading anywhere where the water is present but is of questionable potability, having a LifeStraw or similar might be quite a life-saver. It's small and lightweight and if the push comes to shove, you can drink out of a ditch or whichever malarial swamp you have available.
Thanks! Great tip. I also have some water bottles that will filter water. It is always safest to treat water when you in the wilderness no matter how clean it looks.