One of the things I’m trying to optimise for is my happiness. Hopefully it doesn’t come as a huge surprise that this is a pretty complex thing to do. In my time as an Agile Coach, I’ve read a lot of literature of varying quality on this, and indeed hopefully have helped others to use this to find increased happiness for themselves.
From the studies supporting “Thinking fast and slow” it is clear that present happiness and “remembering happiness” are two very different things, both of which would need to be considered. 
Through my reading of several studies, there is one key thing that I want to call out in this post: social connectedness. It turns out that social connectedness is a better predictor of happiness than any other variable (such as money or education).
As someone going from full-time employment (with a built-in 5-day-a-week social) to self-employment, I was worried that I’d lose a lot of the social connection I had in my life.
To combat this, I agreed to spend 2 days a week in an office coaching teams. I also joined a few local clubs, and committed to myself that I’d go to some interesting meetups.
I’ve also been measuring my happiness day by day, and reflecting on it, in order to cover both “types” of happiness. I draw smileys on my calendar each morning, and do a monthly check on how I feel the last month was.
I know this isn’t very advanced, or even scientific. By using this basic data, I’m trying to understand just a bit more about how I feel, and see whether changes I make (such as joining a club, or doing more running) make a measurable difference to my happiness. Also, through the mere fact that the data exists, I ensure I focus on it more, which is what I want anyway! 
 Kahneman’s TED talk https://www.youtube.com/watch?v=XgRlrBl-7Yg