How do I create a reliable backup of my data?

Do as many of these as possible:

Microsoft Shadow Copy Backup of Shared Folders – Multiple times per day for 30 days (Simple easy drag and drop restore)
Incremental Backups at strategics times during the data (after majority data entry) to Network Attached Storage Device (NAS) (Restore Data back up to 4 hours, quick restore option)
Synchronise Data with Share point to allow data to be accessed from the cloud (File History restore, similar to Shadow Copy)
Backup Office365 Mailboxes *(Acronis E-Mail Security)* (Microsoft 365 DOES NOT backup your e-mail!)
Create Full System Backup Including Configuration onto external removable USB Drives (Rotate at least 2 weeks backups + one Monthly Copy) *(Backup Assist Software with Hyper-V)* (See Blog about Microsoft Hyper V) – Removable USB can be plugged into another server and whole network configuration can be started and run up within 20 minutes in full system loss conditions
Replicate in real-time to an offsite server *(Microsoft Hyper-V Replication)* In the event of Site Failure Replicated server can be brought to site or brought on-line within seconds.