It begins at home. In my experience, 90% of tantrums are at home (becuase that’s where kids spend most of there time), and that is where the rules are set.
If you haven’t taught them there, there is no way you will be able to correct them when at the airport, restaurant, etc... When those 10% of tantrums happen outside the home, the child should already know that Mom/Dad mean business.
Exactly.
Train them at home and there will be fewer incidents in public.
And as WT says, you have to be consistent and follow through.
The kid has to know that there will be a consequence, 100% guaranteed, when circumstances permit.