sorority resume tips?

There really isn't anything extra you can put on your resume without it looking like a try hard. Any kind of resume should be professional and formal, so "interests and hobbies" isn't really appropriate. Anyways, when you fill out your application for rush online it will ask for interests and hobbies.
The most you could do to shake things up would probably be to decorate or format your resume in a unique way so that it doesnt look so plain.

For gosh sakes, PLEASE do NOT "decorate" your resume. We have 3,000 of these things to go through, and I do not need ANY more eyestrain!
Just the facts. That's all. I don't care if you like walks on the beach, long baths in candlelight and quilling.
Just tell me what your organizations are, any offices held, honors, awards.
Keep it short and factual.

Any positions you held (key club president, volleyball captain, even secretary for student government) is good to highlight leadership potential. We want girls who will lead the chapter after we graduate!

I prefer resumes that are not in chronological order, but are grouped by category. It is hard to get an idea of what a girl is all about if her activities and honors are all spread out and listed by freshman year, sophomore year, junior year, etc. For example, if you were in student government, put that under Leadership and give a rundown of everything you did by year. If you ran track put that under Sports and show how you developed from a freshman to winning awards to being elected captain of your team. If you won academic awards put that in a category and then list each one by year. Same with philanthropy stuff. Then you can show what you did and what you care about and how you developed in those things. What categories do you have? Music, theatre, debate, cheerleading, pageants, honors, leadership, sports, philanthropy... And please keep it to ONE PAGE.