Show what you ar editing permissions for on the Permission Screens
When using the backend SharePoint permission screens it should be more obvious what you are editing permissions for. It is too easy to think you are on the Document LIbrary permissions screen when in fact you are on the Site. It should say "Site - <Sitename>" or "Document Library - <Name>" like it does on the front end screens. This can cause chaos if you edit permissions at the wrong level.