I haven't had to quit smoking but I have gone thru seminars about on-the-job stress reduction. The only 2 things that stayed with me are the deep breathing one you mentioned OldBroad and the one about visualizing something that makes you happy.
I had to think for a moment about what always put a smile on my face and then I remembered the comedian Gallagher. It just gave me so much pleasure when he would take a big old mallet and pound a watermelon into smithereens.
Must have been the warrior within me.