Wear and/or bring whatever is comfortable to you. Anything goes. On our last trip I saw a couple wearing a full size Yeti soft cooler. Now maybe it’s me, but if you can afford a $350 yeti soft cooler, why not purchase lunch in the park and be unencumbered! To each their own - carry what every makes you comfortable!I'm starting to get into packing mode for our trip. We're 40 days out. I'm currently making a list for things we need like sunscreen. The one thing that has stump me is what type of bag bring into the park. A purse? backpack? fanny pack? I know those loungefly bags are popular. Are they comfortable? Do they get in the way on rides? Speaking of rides. Are there rides that require a locker for your belongings?