@LukeAlmighty big chungus usb drive for local cold storage, and some cloud account like backblaze to store an encrypted mirror of cold storage. i like to use borg (bup and restic do a similar thing, but bup's support for pruning old records is still 'experimentla') because they deduplicate, so you never deal with full vs incremental and you only pay for updates.

there are other options like rdiff-backup which work a bit different. that ensures the latest version is always available as an unmolested folder while further back files have to be decoded by a script, and there's the rsync snapshot method where every snapshot is a fully realized filesystem (it uses hardlinks so unmodified files don't cost more space)

there's less fun options from there, like dar (its a souped up tar; for the "i like incremental/differential backup hell for some reason" gang) or duplicacy (which i never used because it has some stupid restrictions.)

some folk used to use tarsnap. it had good reviews for a cloud service.