Start with how you work
Before creating folders, identify what you look for regularly: contracts, correspondence, supporting documents or working files. Group files by purpose rather than format.
Keep the structure simple
Limit folder depth. An activity-based structure, followed by year or project, is often easier to maintain than many nested folders. Test it on a real project first.
Name files to find them
Use a consistent order: date, subject, version. Avoid vague names such as final2. A short naming guide helps everyone know what to open and where to save it.
Maintain it little by little
Set aside regular time for filing. Move completed work into a separate archive and review access. A useful system is one you can keep using without excessive effort.