At Butler on bid day when you come back to your dorm room the door is all decorated with your sorority letters, symbols and colors. My roommate and I both went Pi Phi so we were all about angels & arrows but a lot of rooms had two different sorority members in them. I know one room had a Kappa and a Theta in there and around their door there was so many decorations they started taking up down the hallway!
I would recommend cutting out letters from construction paper and putting them on your half of the door to show your pride in your sorority!
Jess