Back in the day, when my school had immediate fall formal recruitment, it was pretty easy. On the first full day that freshmen were on campus, they were gathered for a class picture, followed by a motivational speaker
, addresses from the Panhel and IFC presidents, and the official kickoff of rush. From there, men went off to various fraternities; women went to Women's Convocation, where they learned about their options - sororities and independent living groups (think coed fraternities) - then they could proceed to sorority rush or visit ILGs as they so chose. There was literally nothing to do for a few days except rush.
Now that my school has deferred recruitment, I don't know what is done to get the word out.