Well I don't know about you, but my kids think it's their job to keep the door of my fridge open as much as possible. We are working on that. But even if your kids (and husband) are on the 'keep the door shut' bandwagon, your fridge will run more this time of year. It's hard work to keep things cold in the summer!
A few years back I read somewhere that a fuller fridge is more energy efficient (this is also true for the freezer, by the way). So I try to keep bottles of water in the back of the fridge, along with pitchers of water and lemonade. It encourages the kids to keep hydrated and also helps fill the fridge.
As for the freezer, I try to buy things on sale and freeze them. My freezer has cheese, lunchmeat, hamburger, hot dogs, chicken breasts, bananas (for bread), and various other items. We try to keep it full too.