alright this is a foolproof way to smoke with no smell. me and my friends used this in the dorm rooms and never got caught with this method.

put a fan in the window and block off the rest of the window so little or no air can get in. if you have a second window open it only a little bit for some cross ventilation. towel the bottom of the door. make a spoof (doob tube, w/e) with dryer sheets. you need a good air spray for the air. we found that the brand "neutra air" is the most effective for killing the smell. burn some incense and finally cover the smoke detector with something so it doesnt go off. get some axe for your clothes and visine for your eyes and you cannot possibly get caught.