Not something I often go in for. It's really just not my thing.
I have a few exceptions though, and one of those is this song. "Halcyon and on and on," by Orbital. Youtube link in case you don't know it.
It's the first song I play on any new computer, MP3 player, stereo, speakers, etc.
It's also my re-centering song. Incredibly stressful day (once every couple months type crazy)? I listen to it as a mental break when I'm leaving work, usually in the car or once I've gotten home. Momentous life change? First song I put on in my 'new life.' First song I put on for myself after I got married, first song I play after accepting a new job, will likely be the first song I play for a child should I have one some day.
Or in today's case, "holy fuck the first phase of that project is finally over and I didn't get fired."
I can feel the stress leaching out of every pore on my body, floating away like so much dust unsettling in a film running backwards.
That's my ritual. What's yours?