1) Always Share: Good advice IMHO. If at all possible, you should always have weed of your own — even if it’s only a little shake, it’s good to show that you care about etiquette.
2) Be Prepared: Break up your buds! Tons of smokers just smoke a bud and think that’ll be okay. But you are wasting a huge amount of weed, and making it more difficult to smoke. Ideally use a grinder, or at least your fingers, to break it up!
3) Pass to the Left: Pass the dutchie on the left-hand side (yes, I know weed is not what that kid was singing about).
4) Offer to a Friend First: Good advice for most anything. Always offer to give somebody else the first toke/bite/drink/screw.
5) Know the Pot’s Potency: Nothing will ruin a group’s high like one person having a bad trip on strong weed. Tell newbies when it’s powerful stuff.
6) Puff Puff Pass is OK: Do not hang out gesticulating with a lit joint! It’s rude and wasteful!
7) If You Don’t Have Weed of Your Own, Ask Politely: It’s just rude to jump in a circle without being invited.
8) Don’t Scorch the Bowl: Everybody likes the green, so don’t take it all. Leave a bit for the next guy if possible.
9) Flush the Toilet: Clear the bong when you have finished your weed, so the next smoker doesn’t get a bong full of smoke.
10) Give the Tobacco Warning: A lot of people have quit smoking tobacco, so if you mix it with your weed, give a warning.
11) Watch the Spit: The book Pot Culture recommends using your fingers as a barrier between your mouth and the bowl. This seems ridiculous to me, just don’t slobber all over it. There’s no way the finger thing would work anyway — if you have germs in your spit, they can fit through your fingers. Germs are very small.
12) Keep it Clean: Change your bong water, clean your pipe, etc.
13) Don’t Pocket Someone Else’s Lighter: Another good rule, it’s easy to accidentally pocket a light when smoking. Don’t be that guy.