Be clear from the beginning. Talk about your quirks as soon as you can (so you can avoid blowing up about them later!)
Address things when they’re little. Most of the time your roommate may not even be aware she/he is doing something that annoys you.
Respect your roommate’s stuff. Ask before you borrow, use, or take anything.
Be careful of who you bring into your room — and how often. Your study habits may be different. Your roommate may love quite and you like crowds. Discuss alternating when someone gets the room for studying, if your preferences differ.
Along those lines, decide if overnight guests are allowed and if so, how often. Try not to make your roommate uncomfortable with unwelcome guests.
Lock the door and windows. This is BIG. Theft does occur on campus. Keep safe and lock your room when no one is there and at night when you are asleep. Check out this awesome video by our RAs for more information!
Be friendly, without expecting to be best friends. You do not have to be best friends with your roommate. Awesome if it happens, but if not that is okay. Just stay friendly with each other and you’ll be fine!