Simulate a random disk crash — just turn off the power
Nothing should break — people can keep working
Nothing should break — email and web still works

Rotate your Backups

daily incremental on Backup-Daily
weekly 30 day incremental on Backup-Weekly ( different server )
weekly Full backups ( different server than dail or weekly-30 )

Do NOT erase last weeks backup

keep multiple backups on different server

Test your Backups from Bare Metal Restores
always start from virgin disk when testing backups
always just apply the patches … NO manual changes