I recently bought a box of small Dixie cups to use in the car. They were only a few dollars and have adorable little owls on them that the kids love. Even the Costco individually packaged snacks can get expensive when there are so many of us, so to save more money I just bring along a large bag of something. (gf pretzels, popcorn, veggie straws, snap pea crisps, etc) I grab one of the Dixie cups from the box and fill it up for each child. The cups stay in the car so that they are always available when I need them. In the past we kinda fumbled around with handing each kid a handful of snack or using a napkin or something, but that usually ended up making a mess. I tried washable cups at one point, but they ended up getting left in the van and staying dirty. Disposable cups are not much more waste in comparison to the individual packaging on the snacks that we would have been buying otherwise. They were inexpensive and work nicely for this purpose. We do try to use the cups a few times before throwing them away.
My kids and I each have a water bottle that we fill up and bring along when we know that we will be out and about for more than just a quick trip. If I am planning to run errands, I will fill up their water bottles in the morning and they use that cup for the whole day so that it is ready to grab and go whenever we leave. These are Contigo brand and have worked well for us. I've seen them at both Meijer and Costco.
What tips do you have for feeding hungry kids on the go?