Fill the stem fully with a side of tamp is how I go about it. It is hybrid heat, convection and conduction, so you don't want a dense pack and you don't want it too loose either. I like the medium to medium/fine grind. It is easier to keep the glass stems clean for best performance, the small holes clog up over a few sessions for me. Clean the stem quickly after you finish a session, then I refill it right away to have the follow up session ready & on deck. I've found that the cool stem can be hard to remove even after several months of use (beyond break-in). Dropping the ArGo onto an inverted stem keeps the base of the heater clean but I always check it for bits that fall out, normally only need to dump them out but sometimes I need a tool to dislodge it/them. Invert the ArGo to keep stem facing up when removing to prevent ABV dumping downward.