One thing regularly recommended is to keep a ‘hot thoughts’ diary.
I tried this ineffectually a few times, and then finally years later realised how a good way to work it might be. There are many others, I’m sure.
My version worked this way:
1. Try and write regularly, with a specific aim. Be honest, otherwise it is a bit pointless.
2. Be thoroughly encouraged by writing stuff down. Know that later this effort will be worthwhile and helpful.
3. Look back over, and think about how better you could write in the coming days, so you can adjust how brave and honest you are prepared to be. Use a (green) highlighter if you want.
4. Write something to summarise, and take stock.
5. Keep writing, even when the immediate ‘issue’ has calmed down.
6. Build mindfulness formal practice and this hot thoughts into a regular routine.