It amazes me how much trash, especially plastic trash, can come from a typical homemade school lunch - juice box, individual servings of applesauce, chips, cookies, even pre-wrapped frozen PB&J sandwiches. And if you don't buy the prepacked, then there is usally a flurry of sandwich baggies at the end of lunch. A new school year is when I like to look at how I'm packing lunches and make a small change or two.
I've never been a fan of the individual servings of applesauce, pudding and other treats. So, I've been putting applesauce, goldfish crackers, grapes, nuts, and other little goodies in reusable bowls. The kids know to bring them home to be washed. The bowls are plastic, but I also have a set of very small stainless bowls with plastic lids that I use when I can. (Looking for more!)
Last year I stopped buying juice boxes for school and bought small (plastic) sport drink-type bottle to reuse.
This year the kids got new stainless thermos-type bottles. We are reusing their lunch boxes from last year. I'm experimenting with wrapping their sandwiches in cloth napkins instead of plastic sandwich baggies. I hope to make some cloth snack bags for cookies, etc., soon.
I buy concentrated juice in aluminum cans (Welch's) and mix it at home. We occasionally buy juice boxes for other purposes, but we've cut down on our juice-related waste quite a bit.
I'm sure there's a lot more I could be doing. But, like most people, small changes, one at a time, is the only way I can keep going without getting overwhelmed.