I think the most difficult part of any makeover is getting started. When it comes to closets, they're usually in pretty rough shape by the time you decide to make a change. Sometimes just staring at the cluttered mess is enough to make you close the door and say, "Maybe another day".
The easiest way to make the transition from season to season, as well as keeping your closet tidy and neat on a day to day basis, is by creating a storage system that works well for you and the space you have to work with.