Couple tips:
Talcum powder is handy for giving clammy kids a quick clean. The powder will remove sand and dirt etc without water.
Talcum powder is also good if you've got issues with ants, if you put a small line across their tracks they will turn back and not cross it. If you camp for a few days or more, ants can become an issue.
Cable tie a spare key under your car when you're on a decent trek. When you live out of the vehicle for weeks on end, it is very easy to lock the keys in the car as you break your routines. Locked out of your car in the heat in Knowhereville - sucks!
Photos - Rule of Thirds - Apply the principle to your snap shots and you'll see an instant improvement in your ability to capture the moment http://en.wikipedia.org/wiki/Rule_of_thirds rather than a lifeless image.
Baby wipes are awesome for general purposes. No requirement for water etc for a quick clean or - shower in a bag, as I call it! Work well on halting the progress of mushrooms that grow on the dash on a big trek (dust).
If you haven't done so already, get some mesh or a purpose made matting for the door way / living area of your tent. It helps the grass from wearing and also keeps your living area free from debris.
I'll think of some more later!
Cheers