Enable Security Controls
Enable security controls on your database. While most databases nowadays will enable security controls by default, it never hurts for you to go through and make sure you check the security controls to see if this was done.
Make sure that no default admin, sa, root or other db credentials remain active on the server. Disable, Reset or change all default usernames and password.
Enforce Access Control Lists, only allowing applications to query the server
Enforce authenticated users and group to access only the views that they need to consult