I'm thinking about setting up a pre-production instance, perhaps just Express Edition, for which to smoke test deployment scripts prior to deployment on production. So the scripts go from UAT -> Pre-Production -> Production. DDL triggers and auditing are useful for a DBA, because they can alert you immediately when an event occurs, but it would be nice to have this pre-production environment handy for occasional schema comparisons against production, which would indicate exactly what has been modified outside the official deployment process. Also scheduled backups on the instance would build up a history of point in time snapshots of the DDL and T-SQL code base. Since the pre-production instance is schema only, the backups will be very small and easily accessible.