Happiness can seem like an abstract, transcendent notion, but in fact, I found that getting enough sleep (very important!!), getting exercise, not letting myself get too hungry, not letting myself get too cold (I'm a person who is always cold), made a big difference. Partly because I felt happier, partly because feeling physically comfortable makes it easier to keep other difficult happiness-boosting resolutions like biting my tongue.
I drifted into photography like one drifts into prostitution. First I did it to please myself, then I did it to please my friends, and eventually I did it for the money.