I wrote recently about five tools to use for automated backup. What makes the following tools different is that they are third-party tools. Using the tools mentioned here shouldn't be seen as an alternative to the built-in tools and services of devices but something you should use in addition to them. Multiple backup options via different media and locations make your backup system more robust.

Goodsync - This is a tool used for copying or syncing across drives, devices or services. There are many similar syncing tools and even free command-line options, such as Rsync (a lot of syncing tools are built on rsync as the engine), but this is the one I've used for years. You can think of it as very much like the cloud services and built-in backup mentioned in the built-in automated services and tools, except you have control over what is backed up or synced to what. You can then set it to schedule these backups and file copies.

One example use case is I copy the entirety of my Dropbox to an external drive through a remotely mounted drive (without needing all of dropbox synced on my machine, nor needing that external drive connected to use dropbox).

Backblaze - I've used a lot of options for cloud backup, even leveraging cloud syncing services such as Google Drive and Dropbox (using a backup tool called Arq). Still, in the end, a dedicated backup should be done via an actual backup service designed for it. You have more recovery options, and in the case of Backblaze, with one device per license, its unlimited storage is of excellent value. You can back up any drive connected to the computer (in combination with Goodsync backing up my entire Dropbox contents to an external drive. Which means I can easily back up Dropbox to a third party on the cloud).