I make a handwritten list on a 3x5 card, punch a hole in the corner of the card, and attach it to the pack, cooler, box the gear is supposed to go in. I started doing that a few years ago when all the hurricanes were hitting Florida. All I do is check the list for that particular pack to make sure everything is there.
Also a firm believer in redundancy. Because the most needed tool usually gets shifted around and falls to the bottom of the pack. I also practice finding things in the dark. I HATE it when I have to use a flashlight in the tent at 3 A.M.