ok this coming from my dad, a 5th grade kungfu master; your chi is your power that is combined with all your chakra and all your energy put together, so what I found out by purely practicing the mental/energy act of the coin, I find it easier/better for me to do both, not just visualize but also feel, maybe it's just me but hey, anyway I can't see anything but my energy itself is really powerfull (or so a friend of mine who sees aura's says). First stage of this guy's qi control was to find a very comfortable spot in any place in the room, and mostly sitting with your legs curled up, then he told me to look for my center, my "chakra", asking him what it would be or look like he says: I can't tell you it's up for you to find out, you'll know when you find your qi, and he was right as son as I found it I had this incredible energy and it felt as if I was getting stronger in every body part, but it also felt like something was growing, it's a unique feeling that you can't get easily. Next step was to control that energy and start to move it around in your body, and try to feel it go up to your arms, when you mastered that he got something else for me planned: he gave me a stone and told me to imbue my energy in it once i'd done that (or attempted to) he took the stone and as soon as he picked it up he told me that it was "weird" and something was awkward with me, anyway we're going to continue the exercises later, and i'll post here what I found out about it...