This round is usually the more subdued round. You see a little bit of their ritual and you'll probably have more one on one time with someone you met previously. I still remember all the women I talked to on Pref night and I remained friends with most of them! Just because you are joining one sorority does not mean you never socialize with the other ones! You will be in the Greek Community and that bonds people in the same way being in a singular Greek organization does. It's a tough night for everyone involved! I got so emotional during this night when I was a PNM and as an active. So don't be shocked if you're with a big sap like me and she starts crying! lol! So embarrassing! You'll also be making a huge decision on this day, you'll get to rank where you want to go. For me I had no questions, I knew where I wanted to go but I also had 2 amazing backups just in case they didn't want me as much as I wanted them. Make your own decision! I can't stress that enough. Just because your friends like one house more than the one you want to join means nothing! If you decide based on someone else's opinion you probably wont be very happy in the long run. I know several people who chose their house based on their friends, mom's or actual sisters and they were unhappy. Listen to what your heart tells you and you will be happy!
So this is the nicest dressed you'll be. Here are a few options I think I would wear if I were going through Pref. Just make sure you are comfortable, smile, and breath!