Mike,
Another trick that I learned the hard way was when getting the seedlings out of the 32oz. inverted cup, I used to soak the cup in warm water to release the roots from the side of the cup. This works well, but, it also saturates the root ball with water which could damage the roots later on ( eg. root rot, mold, etc. ).
So what I do now is wrap the 32oz cup with a towel that has been soaked in hot water (tap water). This releases the roots from the side of the cup without flooding the root ball. "We learn as we go..."