A file named final-last-2 usually suggests an absent version rule rather than simple carelessness. People make copies to avoid losing work, and eventually lose track of which copy is authoritative.
Discuss behaviour before folders
Who creates, edits, approves and receives the files? The structure should follow that movement. A system comfortable for one person but incomprehensible to a new collaborator is not yet shared.
Separating source, working, review and delivery material can help. Every project does not need the same depth of folders, though. Excessive structure can make a small assignment harder to navigate.
Agree the stable naming elements
Project, content type, language and version can follow a consistent order. Dates, where useful, should use one format. Names need to distinguish files without becoming needlessly long.
My central rule is that the approved delivery version has one clearly identified location. Other versions need not disappear, but they should not compete with it. A shared delivery link should not unexpectedly open an old draft.
Include access in the design
Allowing everyone to edit everything is not always convenient in practice. Source files can be changed accidentally and sensitive material shared unnecessarily. Required access and retention need consideration together.
An external handover should not contain private discussions or unnecessary personal information. Notes and attachments inside the files deserve review as well as the visible deliverable.
Test with someone unfamiliar
I ask a new collaborator to find the latest approved output, editable source and usage explanation. If they repeatedly need my help, the arrangement still depends on my personal memory.
A searchable content library extends this approach into publishing. Good filing is less a folder tree created once than a small shared habit repeated at every handover.