The policy is easy
Least privilege is one of the cleanest ideas in cybersecurity: give each person only the access required for their work. The difficulty appears when that sentence meets a real environment. Access can come from direct grants, nested groups, inherited folders, public links, old project teams, service accounts, and one-off exceptions. Removing one visible permission may not remove access at all.
Effective access is the real question
An access review should answer what a person can reach and why. That requires walking every path from identity to resource. In SharePoint, for example, a user may inherit access from the site, receive additional rights through a security group, and still have a separate sharing link to one file. A flat list of direct permissions misses the actual exposure.
Prioritize the dangerous combinations
Not every extra permission deserves the same urgency. Focus first on sensitive resources, external sharing, privileged roles, stale accounts, and access that bypasses managed groups. Then identify a safe owner and remediation path. Removing access without understanding business use can interrupt work and encourage users to create riskier workarounds.
Make least privilege maintainable
The strongest design moves access into role-based groups, assigns owners, sets review dates, and records why exceptions exist. Least privilege is not a cleanup project that ends. It is a lifecycle process that should make the correct access path easier than the informal one.