We're very lucky that our children aren't particularly picky eaters. However, both of them are vegetarian and it's very important for me to make sure all their iron and protein needs are being met. I have never been a fan of buying packaged lunch box foods for them but all that unnecessary packaging does not fit in to The Footprints Project at all so they're banned now.
I nearly succumbed to buying individual yogurts last week when I shopped and mentioned this to my son. He informed me that it would be more convenient for him to bring a Tupperware container anyway and to please buy one large tub of yogurt instead of six small ones. Yay. We decided that, as the weather heats up, we can freeze the yogurt the night before and it will be a cold, half-frozen treat by recess or lunch.
We had some split peas in the pantry which my husband fried up and added spices to. They're also in a container at home and the amount is rapidly depleting. Whilst frying isn't healthy, the peas are packed with goodness and we haven't used any extra packaging.
My daughter works in a Chinese restaurant and they always give her a container of food to bring home after work. She rarely finishes it and brings the left-overs to school the next day in the same container. She brings the container home and we wash it up to use to bring food to my father-in-law. We now have a small collection of take-away containers and they've come in very handy.
Finally, both the children like fruit so there is always plenty in the house. It can be sent to school with no packaging involved and then cores and peels thrown away to decompose.