Smell the flowers.
Its been found that people who smell flowers report being three times happier than they were before smelling them.
Being out in nature is proven to reduce stress levels, lower blood pressure and can alleviate depression. Fresh air and exercise, bird song and flowers are all positive mood enhancers.
If you're interested in enhancing your mood by smelling flowers or listening to bird song, I offer walking talking therapy out in nature. Its an hour and a half walk.