Humorous label when the repeatedly worrying thoughts arise:
“I blew it again”
“I can’t get no respect”
“I never get what I want”

Label random worrying thoughts silently before letting them go:
“planning,” “doubting,” “judging,”
“fantasizing,” obsessing,” or
“criticizing.”

Once you label a thought, gently bring your attention back to the breath.

Via The Mindfulness Solution: Everyday Practices for Everyday Problems