1 keep your hands off the other person's food When a carton of your favorite ice cream suddenly appears in the freezer, don't assume that it's half yours. Don't eat even one bite of it until you have permission from tour roommate.
2 Respect need for quiet time. If you see your roommate reading a book, don't constantly interrupt her with conversation. If you know that she has to be at work early the next morning, keep the noise level low. One way for roommates to let each other know when they're sleeping is to have a small "sleeping" sign made that can hang from their bedroom doorknob.