Has anyone ever used a Sobe Bong? You know, the fruit drink called Sobe. There is a small indentation on the bottom of the bottle that you put a nail in and hit it lightly with a hammer, and it breaks out, without breaking the entire bottle. So now you have a small hole at the bottom. Next, at your favorite head shop, buy a bowl with a somewhat short stem, the kind that you would usually slide in and out of a normal bong. Next, cut a small hole in the top of the metal lid that screws on the top of the sobe bottle, and secure the bowl through the hole. I just used some electrical tape, and it worked fine. now whenever you are low on weed and want to conserve, or only have resin to smoke, just fill up your bowl. Then while holding your finger over the hole on the bottom, fill the bottle with water, then screw the top on, filled with the resin or weed. (you don't need much weed or resin to get a very full hit.) then with a lighter, just hold the flame above the weed/resin, and remove your finger from the hole, so the water starts flowing out. as the water in the bottle flows out, it will suck the smoke into the bottle, then just unscrew the top and enjoy!
I've found that since you aren't hitting the weed then letting it burn, like with a pipe/joint/blunt which loses some smoke that could be going into your lungs, you get more out of each hit. since the water is doing the hitting, and it constantly sucks the smoke into the bottle with no break, you don't waste any smoke.