If you ever get around a group of people re-living their glory days in college, chances are the subject will land on roommates at one point or another. There are always the horror stories of the awful roommates, the anal roommates, and the ones that wore your shirts without asking, bringing them back covered with beer stains and/or makeup. But for every one of those stories, there are many, many others where a student met their best friend after being their roommate in college. Chances are your roommate experience will fall somewhere in between. Either way, it is a good idea to be respectful of your roommate from the start to get off on the right foot.
Respecting your roommate starts with communicating with them before you enact any big changes in your shared dorm room or apartment. If you plan to rearrange, redecorate or add a large space-taking item, be sure to consult your roommate and get their opinion first. While you have a right to do what you want with your portion of a dorm or apartment, the minute it affects their room, side or shared areas, you need to let your roommate in on what you are doing.
Secondly, communicate in person if something they are doing is bugging you. If you notice, for example, that they are borrowing your clothes and using your toothpaste without asking, simply tell them your concerns instead of holding it in, growing resentful and trashing your roommate behind their back. It could be that he or she had a roommate previous to you that shared pretty much anything and didn't mind.
Be especially respectful during your roommate's exam dates and finals. You may be studied up, but that doesn't mean your roommate is. Give him or her some peace and quiet and go elsewhere with noisy friends and music when your roommate needs some quiet time.
Finally, remember that colleges are very diverse institutions, so there's a good chance you could end up with a roommate who has a vastly different cultural or religious background than you. These elements make up the core of who someone is, so be as accepting and tolerant of your roommate's background as you can. After all, you wouldn't want to be singled out for your religious beliefs—or the lack thereof—either.