If you're a pot "virgin" or a light weight, let the fact be known. No one likes getting thrown up on or having a passed out stranger on his or her hands due to inexperienced toking.

Always rag on somebody you know can't handle much but still tries to clear a monster bong rip, and coughs their fuckin' brains out and pukes (especially in front of women).

If smoking a joint or a bowl, never put the whole thing in your mouth and get it all sopping wet. It's disgusting.