As I have mentioned before, I enjoy being the watcher of my thoughts.
What this means is that I don't judge my thoughts; I simply sit back and watch them as if I'm watching another person.
If a particular thought is something I don't identify with, I dissociate with it -- and it stops. No need to beat myself up for simply having a thought when I can just put a stop to it and move on.
If it's a thought I enjoy or choose to identify with, I hold onto it for as long as necessary, but not too long, as it might prevent me from discovering my next beautiful thought.
If I find that I have a lovely recurring thought, I'll write about it. Sometimes I'll publish it here and sometimes I won't. Some things need to remain private, after all.
The more I practice mindfulness and as the watching of my thoughts becomes second nature, less negative junk starts to flow through my head -- which means I have less junk to filter out, less junk to dissociate with.
You, too, can be the watcher of your thoughts. Give it a try.