Training to be happy

Think about something that is positive.  Your thoughts may shift back to your to-do-list, work or other stressors in life.  Just  refocus on your positive thought.  This trains the brain to be able to transition from a negative thought to a positive one.

Think of at least 3 things you are thankful for that happened today. This begins to train the brain to search for the positive.

Writing about a positive event or thought allows you to relive this moment.  This trains the brain to seek other enjoyable thoughts.

Looking for ways, throughout one's day, to help others, trains the brain to look for and seek good. 

Increase physical stress to decrease mental stress. After a workout the body releases hormones to return the body to a more stable level.