Try to get in contact with your roommate before you start school in August. Figure out what you each will bring so that you don't end up with two televisions, radios, and six mirrors in the room. Find out your roommates likes and dislikes so that you can figure out what you have in common.
Get a roommate warming gift for your roommate and give it to them on your first day on campus.
Make room rules about cleanliness, food, personal space.
Agree on a way to resolve your conflicts in a calm, respectful way.
Choose one evening or afternoon a week were you just get together and do something just the two of you. It can be as simple as getting coffee, playing a sport , video games or stilling in the dorm room watching a movie of choice.