1. Communicate openly with your roommate. Agree to talk about issues before they get out of control.
2. Accept that sometimes people will be in a bad mood. If she says she doesn't want to go do something with you, don't take it personally.
3. Decide early how the rent and utilities will be split, and what to do if one person can't make the month's payments.
4. Establish rules about food, company, chores, noise, tobacco and alcohol use, and parking. Make sure each person's expectations and responsibilities are clear.
5. Respect your roommate's right to privacy and her possessions. Always ask before you borrow anything, no matter how small.
6. Knock before entering her room.
7. Don't tie up the only phone line ' consider getting separate lines for each of you.
8. Take messages from callers. Get the name and phone number and write it down where your roommate will see it.
9. Begin your statements with "I," as in "I get really annoyed when you leave your dishes in the sink" instead of "You're such a pig!" Focus on her behavior, not her personally.
10. Recognize that some people are neater, louder, more private, or more possessive than others. Don't expect your roommate to mirror your own personality.
11. Treat her the way you expect to be treated.
12. Don't lie. If you screw up, admit it immediately.
Show your appreciation for your roommate's courtesy once in a while.
Don't walk around the house in your underwear.