i always grind up my weed in a metal grinder. i pack bowls loosely to the top, but with the bong (which i use almost exclusively), i only pack 1 hit up at a time. i pack a nice fat hit though. i like this way the best because it is always a nice green hit and tastes fresh. it is a little bit more work, but with an ashtray at hand, it isn't too bad. after years of daily experience i have found that if i take about 4 individual green hits spaced about 5-10 minutes apart, i get much higher, for much longer, than when i used to just pack it up fat and smoke them all in a row.