I'm gonna be using my new VaporGenie tonight and I'm pretty excited, but I just want to know a few things before I get started since I hear the learning curve is tough (I wanna become pretty good at it before the weekend when I'm using it with my mates). First of all, how do I know when my bowl is done or not? Does it look charred or something, or change colour? Or do I have to guess based on how much vapor I'll be inhaling in? Also, I hear some bad stuff about the bic lighters getting flint and other bad stuff into the device that I'll end up inhaling. Can I avoid this by sparking my light away from the device?