Ways to establish residency (for out of state college)?

In the fall I will be a freshman in college and attending a local community college but I want to transfer to ASU after my sophomore year. I was wondering if anyone could tell me how I could establish residency there without me actually living there (if that makes any sense). My teacher told me that Hilary Clinton used to P.O. box to establish residency in New York when she wasn't actually living there. My aunt has a place out there so I would have somewhere to stay (but it is used for vacations so no one lives there all year round) but I need to establish residency.