Make a chart of family rules: for example — «be nice to each other» «talk with a calm voice» Include the child in the process. (dudestodads.com)
There is a good basic family rule for choosing the food and servings: The adults decide what there is to eat - and the children decide how much they will eat. (mambaby.com)
Having clear family rules about «how we do things in our family» helps children know what is expected. (education.sa.gov.au)