The tradition of smoking hookah stretches across many countries and countless cultures. Keeping that in mind, here are some social faux pas that you should avoid.
Never light a cigarette using the hookah coals, it is considered rude and may taint the flavor.
When passing the hose, fold the handle so the tip is pointing at you, never point it at others as it is a sign of disrespect and hostility.
Similarly when sitting, if you cross your legs, do not point your foot or show someone the bottom of you feet. Many people didn't recognize the offensive symbolism of the shoe when an Iraqi news reporter threw his shoes at former President George W. Bush in 2008.
When talking, pass the hose to others who may want to smoke. A hookah hose is not a microphone.
Your hookah should be on the floor and not sitting above you; also when sharing with someone, turn the hookah to give them more slack with the hose, this may also help prevent it from tipping over.