There are many ways to secure a Microsoft SQL Server, but here are five common practices:

• Use strong and unique passwords: Use strong, unique passwords for all SQL Server logins, and enforce password policies to ensure that passwords are regularly changed and cannot be easily guessed.

• Enable SSL/TLS: Enable Secure Sockets Layer (SSL) or Transport Layer Security (TLS) to encrypt data transmitted between the SQL Server and clients.

• Implement least privilege: Grant users the minimum level of access required to perform their tasks, and use roles to group users with similar permissions.

• Use firewalls: Use a firewall to restrict access to the SQL Server from unauthorized sources and limit the types of network traffic that can reach the server.

• Regularly apply patches and updates: Keep the SQL Server and its components up to date with the latest patches and updates to fix known vulnerabilities.