A recent study showed that performing certain tasks can absolutely increase happiness, and gratitude appears to be a key ingredient.
People were asked to write and then deliver a letter of gratitude in person to someone who had been especially kind to them but had never been properly thanked. Other participants were asked to write down three things that went well each day and their causes every night for one week. Others were asked to use one of their top strengths in a new and different way every day for one week.
These three exercises increased happiness and decreased depressive symptoms. Showing gratitude and using our strengths in new ways: That sounds like fun to me.
I posted links to the report on my Habeeb Squared page on Facebook. Read the report, try one or more of the exercises, and then return after you have completed them and let me know how it made you happier.