This may be the most obvious product rec ever, but it is probably one of the most used items in our house hands down. We call my son “snacks” because he literally wants to snack all day every day. He is obsessed with these spill proof cups and carries one around like it’s his best friend. I feel like at this point he will still be carrying them when he is 10 because he doesn’t want to eat out of anything else. A set of two is also only $6!!
Linked here (affiliate).