There are a set of unwritten, unspoken rules in hostels. I should know, I'm a 15 year veteran. To make sure all your dormmates don't stick squid in your sheets or steal your shit...follow these rules.
10) Do not leave open food anywhere but the hostel kitchen. Bugs, dogs, smell, rot are just disgusting
9) If you leave early, pack the night before
8) Lights are OFF from 11pm - 7am. This should be obvious - you are sharing your space with strangers, don't piss them off. If you need light, have a headlamp or flashlight handy, if you are too dumb to bring these, suck it up and go to bed in the clothes you are wearing in with dirty teeth.
7) Changing down to your underwear is okay, even in mixed dorms. Stripping is not.
6) Bring earplugs and eyeshades. Despite these clear and simple rules, people are assholes. Don't get frustrated if a drunk girl starts flipping on every light in the middle of the night, suck it up princess and be prepared.
5) Claim your space. But don't take more than you need.
4) Oh my god, please do NOT pack all your junk in plastic bags....nothing is worse (besides hearing someone's dirty drunk sexcapade) than hearing 30 minutes of rustling through crunchy plastic bags in the middle of the night. Use old pillow cases to store your stuff, or specially designed pack cubes.
3) Quit your bitching about the noise, smell or cleanliness, if you want 5 star then pay for it.
2) Don't have sex. That's disgusting. Use common shower areas, stairwells or dark alleyways for all I care...no one wants to hear your hookup.
And the #1 rule for a happy hostel stay......if you snore, and everyone knows if they do so don't pull the "I don't know bullshit', get a private room. Or risk being punched in the gut in the middle of your sleep from yours truly