Make gratitude a routine, independent of how you feel — and not just once each November, but all year long. 

Gratitude is a divine practice- it's standing up to your limbic system.  It's managing your affective evolved state so it doesn't manage you.  The default untrained attitude is to be overwhelmed by negative emotion + resentful.  You can train yourself out of this. Decide....as and act of will....to focus on what you are grateful for.