Growing Happiness in the Mind comes from the Buddhist practice of mudita, which means 'appreciative joy'.
You start by bringing to mind a memory where you experienced happiness, and recite the following phrases:
May my happiness continue
May my happiness grow
May I be present for the joy
May I appreciate the joy in my life
As you train the mind to rejoice in happiness, you gain many benefits:
Then you expand your awareness by bringing to mind somebody else in your life who has experienced happiness recently. Then observe their joy whilst reciting the phrases:
May your happiness continue
May your happiness grow
May I be present for your joy
I'm happy for you
When you mind wanders, simply come back to your breath and the phrases, visualising yourself or another person smiling to bring up the happiness.
Enjoy this meditation.