I have some friends who recently sent their oldest daughter off to college. The frustration they are having is that whenever they call her she's "just on her way out" or when she calls home it seems everyone is busy.
What worked for me during my college years was setting aside a specific window of time each week for a phone call home. sometimes ten minutes of chatting was enough before I just
had to go to a friend's dorm

, but other weeks it was nice to spend an hour or more catching up on all of the details of my family's lives.
As my family and I continue to live half a nation apart, I still enjoy building our relationships long distance with phone calls home.