Authors with creation rights can make an Inbox for themselves. This is a container that behaves just like Topics or Folders, except that it's always hidden and private, never visible to the public or other authors (except Administrators). Therefore it is in effect a private inbox, where the Author can temporarily add records that are in development.
Authors can create an inbox just like any other record (go to the Inboxes list in Library resources and "Add an Inbox", then fill in the Title field and hit Save). To register an inbox as their own, and Author can go to their account page ("my account" in the right sidebar"), click on the "User Options" tab, and fill in and update the "My Inbox" record number with the record number of the new inbox.
In fact Authors can create multiple inboxes, and add them to their main inbox, giving in effect project groupings for work in process records.
Also since Administrators have access to all inboxes, they can distribute work to authors by placing records in the inboxes of authors that have been tasked to work on those records.
To notify administrators when records have been completed, flag Authors as being moderated (uncheck "un-moderated" in their account "Administration options" tab), so that they request publishing of their records when they are done. This alerts administrators about completed work, as well as providing an opportunity for review and authorization.
For records that are created by more than one Author, add the second and subsequent Authors as Collaborators for the records in question.