What we do with our bodies affects what goes on in our minds. So use this connection to train your body to help you feel better. If you want to feel happier, the first thing to do is sit up straight! And the next thing is to smile, even if you don't feel like it, just go ahead. Smiling releases endorphins into the body, giving you an overall feeling of wellbeing. And then try smiling at someone else. Inevitably they will smile back, which will increase your happiness levels.