SharePoint provides predefined groups and roles that simplify permission management. Familiarize yourself with these groups, such as Owners, Members, and Visitors, and roles like Read, Contribute, and Full Control. Leverage these built-in structures to assign permissions at various levels.

Grant users the minimum permissions necessary to perform their tasks. Avoid assigning broad permissions to entire groups when more granular control is possible. This reduces the risk of unauthorized access and data breaches.

SharePoint follows an inheritance model where permissions applied at a higher level (e.g., site collection) trickle down to lower levels (e.g., subsites, libraries, and documents). Be mindful of this inheritance and avoid breaking it unnecessarily, as it can complicate permission management.

While unique permissions offer flexibility, their overuse can lead to complexity. Reserve unique permissions for specific scenarios, such as when standard inheritance does not meet security or collaboration needs. Regularly review and clean up unique permissions to avoid unnecessary complications.

Conduct regular reviews of SharePoint permissions to ensure alignment with organizational changes. Use SharePoint's Access Checker and Audit Logs  to identify potential security risks. Remove outdated permissions for users who have changed roles or left the organization.

Define roles based on job functions and responsibilities within the organization. Assign permissions to these roles, streamlining onboarding processes for new employees and simplifying permission management as users move within the organization.

User awareness is crucial. Provide training on secure practices, emphasizing features like versioning, check-in/check-out, and document metadata. Remind users to log out when done working to prevent unauthorized access. Foster a culture of data security and compliance.

You could include or add this information in your knowledge base on your SharePoint intranet so that users can always go back to double check the information.

Create security groups for departments, projects, or job functions. Adding users to these groups streamlines permission management, allowing for consistent access control updates. It simplifies administration by updating security groups instead of individual user permissions.

Before significant changes, perform a backup of SharePoint permissions. Utilize SharePoint's built-in tools for backup and restore operations. Regularly scheduled backups ensure the ability to recover data in case of accidental changes or issues.

Stay updated on Microsoft's official documentation for SharePoint updates, patches, and new features. Implement updates promptly to benefit from the latest security enhancements and improvements, ensuring a secure and up-to-date SharePoint environment.