Happiness seems, from time to time, to be associated with any number of different things. I've observed that it is equally possible to be unhappy even in the presence of those things. So happiness doesn't seem to be associated with any particular external experience.
In theory, sunshine makes me happy and drizzly rain makes me unhappy, but I have been sad in the sun and ecstatic in the rain
It comes and goes like the tide, quite independently.
I suspect that serotonin levels have got a lot to do with it. In which case, rational thought, a balanced diet, interesting work, friendships and plenty of exercise should all help towards the most happiness for the most time.
When happiness goes off to hide, acceptance and reason will get you through pretty well until it pops up again.