Camping near a beach?
We never camp, especially if there is a beach involved, without a huge container of "baby cornstarch powder". We sprinkle it on the mat outside and inside the tent to remove sand from the bottoms of our feet so it doesn't make it into the sleeping bags. We also keep some in the car in order to keep sand from taking over the floor. It also works to get sand out of your kid's scalp and your baby's diaper area.