I would get eye to eye with my children and tell them how they were expected to behave. If I had to leave a store because of their behavior the got their bottom lit up when we got home.
With 4 children I only ever had to leave a store 1 time.
My youngest was very bold and would tell other little ones off when she saw misbehavior.
One time she told a mother "You need to spank his butt.". Lol. 4951