What do you look for during rush?

Hi, everyone!! I am going to be a freshman next year, and I am really excited for rush. I was wondering, for all of you that are in sororities or fraternities already, how you decide who to invite back for each set of rush and who gets bids? What kinds of things (good or bad) make you really like someone or decide they are totally wrong for your organization? This message board is really great... I have learned tons on here already! Thanks so much! -Jen