Our last trip was the last one we'll take with a stroller unless we are blessed with more little ones. We used a soft-sided cooler that had a hard-sided insert to keep things from being squished in the bottom of the stroller. We were surprised how much we liked being able to stop almost anywhere and eat lunch. We packed sandwiches, mini-pringles cans(contraband at home, but again...wouldn't get squished and we reused the cans for cereal and trail mix,) apples, oranges, and maybe some other small snacks. Each member of the family had a camelbak straw cup, and we carried the little flavor packets to keep our boys chugging water and staying hydrated (again, not drinks they get at home!) I'd use something you're used to...what works when you go on other day trips at home? The only thing we did differently was to use a combination of reusable and disposable containers for snacks and food, while we use primarily reusable stuff at home.