I'll start with a disclaimer: I am by no means an expert.
But in the last 9 months, I've spent 11 weeks in 9 countries staying in hostels, so I have at least some idea.
I've had my share of grotty experiences, from shacks in Ayuthaya with only a fan to serve as "air conditioning" in the 37-degree heat and witnessing drug deals on an adjacent bunkbed in Vienna, to Tokyo dorms that more closely resembled pigeon-holes in post rooms and a Hong Kong digs with no shower.
But I've also had the best of times. That place in Tokyo is where I've made my best travelling friends. There's been a 6-person room to myself in Seoul, a free in-house onsen in Beppu, traditional tatami-matt rooms in Nagasaki and a guest-house built by the owner's own hands in Nara.
So here's my guide on how to not be a dick in hostels.
DO: take off your shoes. Especially in Asian countries, this is a big thing. But in general, unless the floor is made of lava, taking off your shoes at the door - at at least within your dorm - stops mud getting tracked everywhere you're living.
DO: be neat and tidy. Everyone is crammed in the same living quarters. Be on your best behaviour. Play nice.
DO: pay your dues. If you borrow someone's shampoo, lend them your razor or something. Mooching is not okay. And if you're in a position to help someone, do - which is why I am now apparently the "saint" of Nishi-Kawaguchi, after patching up someone's bleeding forehead with my handy first-aid kit.
DO: talk to people. Everyone. You might not get along with everyone, and that's okay. But you'll be amazed at who you meet - students, teachers, barmen, engineers, corporate drones; everyone in a hostel is there for a reason, and it's probably insatiable wanderlust.
DO: pick up other people's slang. I came back from a six-week trip with "aye" ingrained in my daily vernacular, and I am currently touting "Oh, I wouldn't say possibly, I'd definitely say for sure," on an irritatingly regular basis.
DO: realise that "where are you from?" is likely to replace "what's your name?" as an opening line. I've hung out for hours with people only to realise I have no way to identify them other than "the really tall Swedish guy" or "that Mexican guy's girlfriend".
DO: take chances. We get taught that there is danger around every corner, but travelling teaches you strangers are mostly kind. Have a drink or two, or three or four. Make friends. Go to karaoke and play football in the park. Appease the police. Kiss strangers. Laugh as much as you can.
DON'T: be noisy. So shut up in dorms. No calling friends at noon, because people WILL still be sleeping. No laughing drunkenly on the porch, and no sex. Okay, none of these are going to hold - but you should at least try and be quiet about them.
DON'T: do anything illegal.
DON'T: expect everyone to be your new best friend. Some people are just dicks. Accept it and move on.
DON'T: spend two hours in the shower. Especially if there's a very limited number. Get in, get clean, wash your hair, bugger off.
DON'T: feel guilty about engaging in behaviour that you would otherwise frown upon. A few cigarettes and make outs won't kill you, and it turns out that sharing someone's last smoke is a surprisingly good bonding experience.
DON'T: expect it to last forever. And at the same time - don't forget about it either.
Memories are all we have, really, as humans. Don't ruin someone else's. And let other people in - they're the ones who will make your memories really precious.
Go now, and hostel like a nice human being. And not a dick.