Most of my data is backed up to (or just stored on) a VPS in the first instance, and then I backup the VPS to a local NAS daily using rsnapshot (the NAS is just a few old hard drives attached to a Raspberry Pi until I can get something more robust). Very occasionally I’ll back the NAS up to a separate drive. I also occasionally backup my laptop directly to a separate hard drive.
Not a particularly robust solution but it gives me some piece of mind. I would like to build a better NAS that can support RAID as I was never able to get it working with the Pi.