I haven't, but I plan on getting some books and reading up on it/practicing. I'm 16+ weeks now and spend alot of time practicing relaxing all of my abdominal muscles and pelvic floor muscles. I can't wait to read up on some of the other methods of relaxing and start practicing now! I'm hoping to make it without any pain meds at all. My second daughter, first vaginal birth, was a 14 hour labor preceeded by 2-3 days of false labor. I made it through the false labor and about 11 hours before giving in for some IV meds. Never did get an epidural. :)