one hitters work the best imo because u can limit how much weed and its easier to tell how much more you need, might take a little longer to smoke tho. What i do to conserve as much as possible is break down my weed as much as i possible can (usually to crystals, i do it by hand but you can do it with a grinder if u have one) and then smoke out of one hitter then wait a few to see if i need another