I started with a BBW/Coti natural combo and used it successfully for years. Added a CH12K a few years ago and shaves got a touch smoother.
Since I only had the one stone, I guess that I pretty much mastered it but there wasn't really anything to it. Hone. Test. Hone some more. Test. Maybe I got lucky with my stone. Based on my personal experience, I would say that cotis are a great stone to start on but I guess others who have owned more than one coti tend to disagree.