1. Do. Your. Research.
hostelworld.com is a great tool to use while traveling. It rates the hostels based on different categories such as cleanliness, staff, location and so on. I tried to book hostels that had the best ratings from the most amount of people and had great success finding wonderful hostels.
2. Do make sure your hostel is in a good location.
Pull up a map if you have to because there is nothing worse than getting to your great hostel and realizing its a 25 minute, expensive train ride from the city center. The location of a hostel is absolutely essential to the experience.
3. Stay in co-ed dorms
Especially as a solo traveller. I have never had an uncomfortable experience in a hostel involving a guy. Everyone tends to be very respectful of your personal space. I had the best times in co-ed dorms because there are more people in them, the people staying in co-ed dorms are usually really fun people who aren't uptight and I had the best luck meeting fellow travelers this way. This may not apply to anyone who is trying to get a full 8 hours of sleep because the more people that are in a room, the louder they tend to be. I once stayed in a 8 person all female dorm room and it was full of girls who went to bed at 8:30pm, only spoke french and were all traveling together so I felt very isolated and left out.
4. Don't have sex in a hostel dorm room
5. Don't get so drunk you can't get into your bunk.
I have been on the bottom bunk when a Canadian fellow came in wasted and made several very loud attempts to get on the bunk above mine. When he did eventually make it up there, he thew up all over the place and my backpack still smells like vodka cranberry vomit.
6. Don't be the person who sets an alarm and doesn't wake up to it
It has happened in nearly every hostel room I have ever stayed in and it's just as annoying as the first time it happened. Now understand that there could be up to 30 or more people in a dorm room at a hostel and people have planes and trains to catch so people have to set alarms. But make sure you're going to wake up to it because it is very irritating when someone's alarms goes off 27 times before someone finally throws a pillow at them. Not a good way to make friends.
7. Do make sure that you're in your correct bed.
In my very first hostel I was given a room and I chose a bed and when I came back later some guys stuff was on my bed. I was irritated so I moved all his stuff to the floor and went about my business. Later I was venting to someone else about it and they were like "Wow how rude of him. Doesn't he know that he has an assigned bed?". Assigned beds? I looked at my room key and there it was, a bed assignment.....ooops. Sorry British fellow who's belongings I moved. I went upstairs and quietly moved my stuff to my actual bed. Lesson learned. Some hostels, in fact most hostels don't have assigned beds and you just take whatever is available but if you do have a bed assignment make sure you make note of it.
8. Do make sure you take advantage of the staff's knowledge.
Most staff working at hostels have been there for long enough to know the best places to eat, the best bars, the tourist traps to avoid and even dangerous areas to steer clear of. The staff at hostels can arrange taxis for you, give you day trip ideas and can help you get involved in super fun activities like pub crawls. The first thing I do after checking in and getting settled is go make conversation with the staff! Tell them where you're from and they'll do the same and then you can start gathering information.
9. Do take advantage of hostel coordinated activities.
Things such as pub crawls and hostel coordinated outings are generally a lot of fun and it's a nice change of pace to be able to relax and let someone else do the planning for once. The staff typically do a great job of making sure the outings are fun and it's a good way of meeting other people. Nothing gets people chatting like a few pints of local brew. However, take note that generally pub crawls take you to the most popular bars in town so if you're not into crowds then maybe they're not for you!
10. Do buy some great ear plugs
Snoring is a real thing in hostel rooms. With that many people jam packed in a room, one of them is bound to be a bad snorer. And if they're drunk, it's way worse. Ear plugs were something I over looked while packing for my trip and they would have been very handy, luckily most hostels are prepared and can sell you some cheap ones to get you through.
11. Don't flick on the lights at 3am
Story as old as time. The pub crawls finish at 2 or 3am (sometimes later), and the hostel gets flooded with the most obnoxious drunks in the middle of the night and they turn on the lights and stand in the hostel room full of people trying to sleep and talk about a football match or that hot girl at the bar they just left. Don't be that person. Hostels are loud by nature but have some respect. People have activities planned and planes to catch early and not everyone is there to be up until 4am and sleep in until 2 in the afternoon. Discreetly use your phone flashlight to get what you need and then head to the common areas of the hotels if you want to chat.
12. Say hello!
Being social is always good in a dorm room. Say hello to your bunk mate and reach out to other solo travelers! You'll learn that "where are you from?" is the most typical way and usually the best way to break the ice and make friends!
13. Leave politics at the door.
There are people from all over the world staying in hostels at the same time so naturally differences in countries come up. And it can be a great learning experience talking with people from other parts of the world so I'm not saying don't take the chance to learn about other countries while you have the chance. But let me tell you that visiting Europe during the election year was one of the things that made me so excited to get out of the US for a while, but I still had to hear about it everywhere I went. Everywhere I went people wanted to talk about Trump, ask me my opinion and freely give theirs and it was very irritating. Just tread lightly when it comes to politics because you don't know people's views and everyone is just there to have a great time so don't ruin it with going on about the morality of the death penalty or the use or non use of gun control.