I don't really have many negative thoughts.... Just get a feeling of negativity. A hollow feeling.
It's not as intense as it used to be, but it still does come up from time to time based on conditions and time cycles.
The quickest way to get out of it for me, is to help others.
It disappears almost instantly. That feeling.
I'll sit there and analyse it (especially if I'm too lazy to discard it from my mind), but the way it goes is to either move, or help others.
But helping others has more power, by far.
Moving is great - exercise, go for a walk, because it will change your state of mind.
But helping others not only changes your state of mind, it fills it with the greatest joy there is.
To help others is to help your true self.