If you're talking storage... like your Media files (music, photos, documents)... then it doesn't make sense to use an Image Backup... Image backup are really for O/S drives and you also can't restore individual files with some versions.
Now, to answer your question. Most backup software allows you to create File Backups on schedule. The good part about that is.. if you have lots of different folders/locations... you could create a "task" that includes all your locations... and do one click backups. Some software can be told to only copy new versions of the same file.. but speed wise, this type of backup will take a bit longer since the computer had to first check to see which backup files need updating.
However, if you want to just do a Copy/Paste with your folders... that's also good. It's the cheapest solution and doesn't require your computer to have extra background jobs or processes running 24/7 an it's also the fastest.
I think it just comes down to a matter of convenience and how well your computer is organized. They way I've always set up my computer is... Documents, Music, Photos, Videos are always relocated to a different physical drive. That makes image backups of Drive C, my O/S drive extremely quick and keeps the drive size small.