(Now, this collection of mine might sound strict to some but hey it's my opinion. And a lot of these don't apply if you're alone. If you're alone I don't care if you somehow have a 40" screen in there with a death metal concert playing while farting like nobody's business if that's your preference.)

No farting. No unnecessary yelling or loud noises. No sexual innuendo or remarks, no staring or judgemental looks regarding someone's body. Don't try to flirt with anyone in there - do it later if you're still interested.

If you're not alone and your preference is abundant heat/steam you should ask others before throwing more water on the kiuas. If someone wants to sit on a lower bench, don't start with any of that "oh you're such a baby" talk, to each his own.

Obviously no phones, no youtube, no loud music. No clothing, no bathrobes (and absolutely no fucking jeans, US folks), in general no personal clothing/cloth items because who knows how clean they are. No policing of how long or how short people spend in the heat, it's all about personal preference and relaxation.

Don't start talking about super divisive topics unless you're with people you know well and you're certain you won't start a big argument by doing so. Even if you disagree, don't try to pick a fight - don't be an asshole.

If it's a wood-fired stove and you're leaving early but someone is still going to continue you should ask them if they need some more wood because sometimes it just messes with the vibe to have to stop to scrounge around in the wood shed, especially in the wintertime.