Observe your moods. Take notice when you feel an unpleasantness. What are you thinking about?
Inner dialogue example:
Uh oh, I think I just said something stupid.
Now I feel like an idiot.
Hey wait, I just noticed that I’m feeling poorly right now,
I’m going to stop thinking about this.
Hmm, but I do feel kinda dumb.
Oh, oops! I’m doing it again. Haha! Okay I’m done.
Let’s see, maybe I’ll have salmon for dinner tonight.
Over time, with practice, moods can be consistently improved by pruning negative thoughts.