Backups that actually restore

A backup you have never restored is a hope, not a backup. The routine I settled on is small enough to keep doing.

Back up the data and the configuration, but not the operating system; a fresh install plus the configuration is faster than any image restore.

Keep at least one copy somewhere that does not share a failure with the original: another provider, another region, or simply another continent.

Once a quarter, restore into a scratch machine and start the service. If it does not start, the backup was incomplete, and now you know while it is cheap to fix.

Write the restore steps down next to the backup itself. Future you will have forgotten the details, and will be doing this at an inconvenient hour.