What are the top three things you need?
Coherence of values within the society. Being happy is being coherent with ones values, and that is easier if the surrounding society holds the same values (within reasonable limits that is). That includes laws and rules based on those values.
Education. Being taught to think, to learn and to consider. Being able to be critical of the status quo makes that one does not accept the marketing "happiness" just like that, but empowers to find ones own definition.
Can't think of a third one, actually. I think with those other two the base is quite strong, if achievable.