1) Spend time checking out how much room you have and how might you best organize your stuff so that it doesn't get in your roommate's way.
Think like this, "I have a lot of books..." so most likely you will need book shelf space. "I have a lot of health and beauty items..." so you will need plenty of cabinet or drawer space. Take a look at what you have and what you know you will be using on a daily basis and be sure those items are accessible. However, don't go overboard with organizers when you know your area is limited.
2) Do not post any wall hangings or display keepsakes that are offensive such as political, religious, intolerant, or racist.
This seems like an obvious point, but you will be surprised at what you might think is "okay, alright" while someone else thinks your interests are highly offensive. Keep your odd interests out of view until you get your own place.
3) Avoid asking to use or borrow your roommate's stuff and don't volunteer your items.
If you want to avoid future arguments, establish boundaries and not free for alls. The items that you enjoy the most will be used and your kindness taken advantage of when you have that "mi casa, su casa" attitude. If you don't sincerely mind someone touching your things, don't allow it and don't use theirs either.
4) Unpack items immediately and don't leave your belongings in disarray.
Cardboard boxes are magnets for spiders and other insects, so do away with them. If you must store items, use plastic bins. Avoid bulky, whimsical and bright furniture especially if you have no plans on utilizing and living in the space for long. Choose items that go well with existing furnishings.
5) Be sure your area is neat and smells appealing at all times.
Odor lingers in carpeting, bedding, and laundry, so do be sure you are aware of your body odor and clean linen, carpeting, etc. and spray deodorizer.
Before moving from your single room or dwelling into the shared space, be sure you have already donated, sold, threw away, and kept necessary items. Do not bring along things that you know you just don't need. The more you keep, the more clutter and also the more headaches for your roommate. Give yourself a self-talk on why it is important to rid yourself of some things or pay for storage elsewhere before someone has to later sit you down and explain why you simply have too much stuff and why it would be better for you to move.
Nicholl McGuire is the author of What Else Can I Do on the Internet?