SharePoint works best when people understand where information belongs, who can access it and how sites are managed over time.
Establish clear information architecture
Use a consistent approach to sites, libraries, metadata and navigation. Avoid creating a new structure for every team without an overall model.
Make ownership visible
Set site owners, review access periodically and establish simple lifecycle expectations for content that is no longer current.
Balance control and usability
Governance should be proportionate. Document the rules, explain why they exist and make common tasks straightforward for staff.