I usually pack fruit, once in a while a grain product like crackers or veggie sticks like peppers, grape tomatoes, celery, depending on the age of my group. We take the bus when we travel and the first time the bus didn't show up was when I learned to always take some food. I also pack all their juice sippy cups when we are out and about. Sorry, but I wouldn't feed my little ones trail mix because they would probably drop it all or choke on it. But an older group would be fine with it. If you google you can find great recipes.