Although cleaning top rope anchors is a fairy straight forward task it still leads to many close calls and accidents every year. In this video learn the foundational skills to clean top top anchors and be lowered off of a single pitch climb with help from the American Mountain Guides Association.
The issues of when to lower or when to rappel is a complex one and has no perfect answer. The most common way to get off a crag pitch is to lower and many crags have been set up with lowering in mind by installing easy to replace rings or twist links. That being said many crags have a local ethos of rappelling whenever possible and this is certainly a best practice when anchor wear is a concern.