We had a whole thread about this last year. You might want to check it out for ideas.
http://www.greekchat.com/gcforums/sh...d.php?t=125180
My initiation chapter is currently wearing jeans and tshirts for First Round, green dresses for second round, and black dresses for pref.
There are more sets here:
http://deltagammacj.polyvore.com/