I listened to an interview with a therapist the other day. She described a technique that she uses for her patients who struggle with anxious rumination.
The technique is to schedule a 15 or 30 minute block in your calendar each day, and to call that your "worry time".
The idea is that when you notice yourself worrying or ruminating about things during the day, getting lost in thought, you can just say to yourself "ok, I'll come back to that in worry time". And this makes it much easier to let go of the worries, because you kind of know that there is this moment in the day where you're allowed to worry about things, or think about things, try solving you problems.
And then, when it comes to worry time, you can set things up to *worry* *usefully*. So you can have a notepad and do journaling, or whatever it is. And she said that this technique has greatly helped many of her clients, as a sort of enabler of the general letting go approach.
The therapist's name is Pia Callesen. This idea was presented as part of a broader discussion of metacognitive therapy.