Haven't done the cold plunget yet. Did get the Wim Hof fundamentals course for Christmas last year, and that worked on breathwork as well as cold immersion. I got to the point of taking cold showers (about 50 degrees) for 5 minutes. I'll also step outside, in Colorado, for several minutes with the cold in the 30s (or much lower).

I do sauna for about 20 minutes post workout.