Check Database consistency at-least once every month.
Do proper capacity planning for the growth of your Transaction log file and size them accordingly – don’t leave it to Auto-grow on default setting to avoid performance hit.
Transaction Log files cannot take advantage of Instant File Initialization.
In your backup strategy avoid taking daily backups of your read-only databases, monthly full backup is more than enough.
Rebuild only those Indexes where the fragmentation level exceeds the threshold value of 30.
Configure a dedicated NIC (network card) card for your Backups on your busy systems.
Always use SQL Server Configuration Manager to change Service account for any SQL Related Service.
While referring objects in Stored Procedures, functions, views and Triggers always use Fully Qualified (Multi Part) Name of the object.
Enable “remote admin connections” on all your SQL Servers to be able to take DAC (Dedicated Admin Connection) remotely.