I forgot where I learned it originally, but what also works for me sometimes in particular instances is asking myself "Is this thought mine?" It's effective when I catch myself ruminating on a hot topic or current event and getting upset over it. Meanwhile, it's usually an issue that I have no control over and doesn't effect me significantly in the long run anyway. In this age of social media, I think we tend to feel we HAVE to be opinionated more frequently, even on subjects we have nothing to do with or care about all that much. There seems to be more societal pressure to "pick a side" in games we might not even want to play.