There's a thing that we used to do, we referred to it as "Jamaican hotbox". It is one the best ways to fill an entire room with smoke. You need to smoke in your bathroom though. Close the door, wet towel on bottom of door crack, Turn on the sink faucet all the way with only hot water, and then turn on the shower and only run hot water. Let it run for a minute or two, letting the bathroom get a little steamy. Then light up a big joint, It will fill the entire bathroom with smoke, like can not see your hand in front of your face so much smoke lol. It used to be all the craze back in my teenage years, it was always so much fun, not even being able to see your friends on the other side of the bathroom lol. You have to give that a try sometimes, Its awfully fun, happy toking.
P.S, hot boxing is very common for people who regularly smoke marijuana in their car.