On my mission, my companion and I attended a potluck dinner for a ward activity. After everyone had finished eating, my companion and I helped clean up.
For the meal, we used regular dinnerware from the church. I went to one table and stacked several plates for ease in carrying them to the kitchen. As I brought them into the kitchen, one of the relief society sisters took them from me and stated, "Elder, never stack up plates like this ... because then you have to wash both sides of the plate."