For me my body naturally knows when to stop. You start getting too lazy to toke. Like "Naawww... I think I'll just set it down now... Im stoned." Inhale is the key though. Inhale hard and deep. You want that smoke to feel like its in your stomach. Who knows, you might end up smoking it all, or maybe half. I find a gram ((half of what you've got)) is enough to get me nice and stoned. Sometimes I even smoke less then that. Sometimes more. -shrugs- Apple pipes are nice. Make one. ^^ But if you want to make sure you get stoned, and waste as little weed as possible, I recommend a home-made gravity bong. Just google search "how to gravity bong" minus quotes and your good. It hurts your throat, but if your weed really is very good shit ((which I doubt you'd really know seeing as you're a first timer. I've been smoking for a month now and it's always pretty hard for me to know until I smoke it)) it should take you 3 hits MAX, if you take the hits like a man. ^^ BTW, dealers always say "This is some good shit"