Well, usually I don't have any balloons around, so in the rare occasion that I buy a few cans, I just tip the nozzle of the whipped cream slightly. Just enough so that only air comes out, and no whipped cream. You'll hear the nitrous coming out, it's pretty loud. You put the nozzle in your mouth, and inhale until no more air comes out, then hold it in your lungs for as long as humanly possible. It is VERY VERY intense when used properly. Some people buy the nitrous chargers used to make homemade whipped cream off websites or porn stores, and buy a 'cracker', which is a device used to crack these open. The nitrous is emptied in a balloon. Then, the user will inhale the nitrous in the balloon, blow it back, inhale it again, etc, until you feel the full effects. Or you could just keep it in your lungs for as long as you can, like the previous method I mentioned.
