Ahh etiquette!!!!! Try to pass on what i've learned to whoever I meet.
Puff, Puff, Pass. don't over toke the joint.
Pass to the left. If not then its all good.
Don't take the roach if you didn't roll it. Offer it to the roller and if they don't want it, it's free game.
Only green half the bowl. No need to light the whole top of the bowl and then pass it.
If someone gives you a bong bowl, ask if its a personal bowl or community. I assume bong bowls are "bingers" personal 1-rip bowls, unless noted otherwise.
Don't diss the weed if it ain't yours.
At least say thank you after being smoked out by another person. Weed aint free ya know, the least you could do is say thank you.
Don't call everything chronic. (Hate hearing from a dealer that he's got chronic every week really throws off the chronic meter
)
Don't pause on the bowl and start talking your head off. Hit the bowl then pass it and talk all you want.
If your sick, please inform other smokers before hitting the pipe/joint. I hate getting sick from smoking.
Got a few more but can't think of them at the moment.