The problem with file backups is you still have to deal with the operating system and potentially all the programs if the hard drive fails (can lose things like your bookmarks from your browser too). I find it much easier to just image the disk every week or so and then have an emergency disk created so you can boot the computer if the hard drive fails. You can also move the entire works to another computer pretty easily with an image file and the appropriate emergency disk (assuming they are comparable computers capable of running the same programs).
Windows, Dropbox and other cloud based systems make very easy to back up your files on a regular basis. You just have to go into Window's settings, update and security and then backup. The options make it possible to automatically back up your files from a folder like documents regularly. You can then restore a single file or two. The windows setting for image files is found under the looking for an older backup on the same page (works fine in Windows 10). Cloud based services like Dropbox also make it possible to automatically backup to the cloud on a regularly set schedule.
One point you might want to consider too is security. I would unplug your portable drive once the image or backup is complete for the week of whatever time period you establish. If you have an image file, you can over-write a disk in the event you get a nasty virus (particularly if it has not spread to your portable drive). I have never tried to re-image with a ransom-ware attack. If you are able to boot the computer with the emergency disk, it should be theoretically possible to image the drive and eliminate any unwanted code from a ransom-ware attack (maybe others have more experience with this situation).
Of course, none of this is relevant if you have an Apple Computer (other than the house-keeping ideas).
= new reply since forum marked as read