we have rubbermade totes. One is our kitchen which as all of our cooking stuff, dishes and dish washing stuff and spices and koolaid mix etc.
we have our tent which also includes tarp, extra rope, stretchy cord, water proofer, tent freshener and tent broom.
one with our sleeping bags and camping pillow, pads etc.
milk crates with smaller stuff-
one with camp toys and one with swimming stuff.
dog stuff in one
towels and bathing stuff in a solid tote bin that we use as a wash tub.
for packing clothes everyone brings their own soft side bags. dirties go into a giant stuff sack. and I never pack extra or at least never consider anything that has been on a camping trip clean . . . so I don't worry about keeping things too separate. Also I make my kids wear the same clothes every day until they are just too gross. That way re-cycle any bug spray that was on them
the only thing we have to pack each time is food and clothes. If you go camping every weekend, every other weekend I would head down to good will and get some cheap camping clothes so you can just repack them right out of the wash. Thats what my aunt and uncle did with their kids. They would actually wash them while they were gone and leave them in the camper.
also pack some easy camp foods (the fantastic brand mixes are great for this and taste awesome. also pasta and jarred sauce, pancake mix etc) and keep a pantry stocked and ready to grab. You can put in canned fruit and veggies. powdered milk and cereal. then all you have to grab is fresh stuff.
and in our car at all time during the summer is sun screen, bug spray, first aid kit, bubbles, side walk chalk and baby wipes. . . . .