Regarding the right/left question that was originally posted, my opinion is that using both hands is quite useful. I felt very awkward using my left at first, but I very quickly became almost as good with my left as with my right. I'm sure the learning curve is different for everyone, but now that I'm comfortable with both, I find myself switching hands quite a bit (withouth really thinking about it) as I try to get the best angle for various parts of my face. I consistently use the right hand for right cheeck and vice versa, then left hand for right neck and vice versa. For my chin and upper lip, I find myself switching hands more in order to get the right angles, especially when I'm touching up any missed spots after my standard WTG and XTG passes. Even if you find it difficult, I recommend sticking with it for a few weeks to see if you can get more comfortable with your off hand. I also brush my teeth left handed now for practice - seems to help.