To make your life as a user or administrator more easy you could start with the following concept and build onwards/adjust from there.
I did not visually work it out (yet) but as a starting point I use the following “ruling”:
- Personal documents with incidental sharing (HINT: point the Windows My Documents to the local OneDrive sync folders location)
- Team collaboration “work in progress”/draft documents (The digital war room principle)
SharePoint Team sites
- Document archive and publishing to a larger team/ department/group of people (SharePoint Team site)
- “Public” documents (Intranet site) / News page related (published) documents
- Documents with a minimal archiving period
- Documents with specific version management
- Documents with publishing approval
Yammer (in case Yammer is actively used as an inter company social platform)
- Documents with social info / nonwork related data – not important who does or does not read or can access the document – no retention requirements
This is only a guide so you can start working with documents within some kind of boundary concept with the benefit of “all faces in the same direction” group work.
Review this working method/policy within your group and adapt based on your experience and needs.
Have filing fun!