I generally pack one protein/whole grain item and either two veggies and a fruit or two fruits and a veggie.
Protein/grain - PB&J on whole grain, grilled cheese on whole grain, hummus, left over pasta with whatever meat/veggies we made it with, plain yogurt with fresh fruit chopped in (covers fruit too), left over black bean chili
Veggies - broccoli (raw or cooked), green beans, peas, corn, salad, carrot sticks, sweet potato, greens and beans (kale w white beans), guacamole (cover top closely with plastic wrap or it will discolor), seaweed salad, edamame
Fruit - bananas, clementines, oranges, melon, strawberries, blueberries, pears, peaches, grapes, dried fruit (when we run low on fresh - raisins, craisins, apricots, prunes).
My husband - um, he takes care of his own lunch.
I do NOT use a thermos - they seem to keep food warm (ideal bacterial growth temperature) and not hot. My son is perfectly happy to eat virtually all leftovers cold (I do too, so I do not feel like this is any sort of problem)