When I went through rush I followed the guidelines given to me before the week started.
On the first day we wore jeans/shorts w/ the recruitment t-shirts & it got a little dressier as the week went on. I only wore a skirt the day of pref & on the third day into recruitment I was still wearing jeans w/ sandals & a very nice button-up shirt. I remember one of the girls in Sigma Kappa approached me & said "You look comfortable" & I thought she had meant it in a mean way. But after I accepted my bid she came me & explained that she really liked how I wasn't trying to overdress just to impress them.