Say one thing you're grateful for today, and why.
Saying thank you for the meal, for help or for a good moment is easier to learn when it is noticed and celebrated rather than demanded.
Kalmdix announces the mission as a playful quest at the start of the meal, then lets the children talk about whatever they like. It works on one habit over five meals; on the fifth, the mission is a secret. Kalmdix never says who did or didn't do it: the results appear after the meal.