1.While your friend is slumbering peacefully within their sleeping bag, shove their head completely inside, and close the opening.
2.Before they are awake enough to fight back, open the bag a bit, and fumigate their sleeping bag with some stank ass gas.
3.Trap them in the bag until they pass out, or start crying.
When you open the bag, it should smell like you are opening a fresh bag of Lays potato chips.
SIDE NOTE: Everyone loves getting layed. Do it to all of your friends. They may look like they are suffocating on your rank fart cloud, and about to pass out or die, but they are really having the time of their life.