Drive imaging is the way to go.
But first, let's clear up some terminology, so we're all on the same page here.
There are three different approaches to copying data for backup purposes.
1. File and folder backup. This is what most simple backup strategies attempt to offer, but it can be tricky to make sure that all of your important stuff gets backed up.
2. Disk cloning. This specifically refers to moving the entire contents of one disk to another drive, to be used as a physical drive. For one use case, say you want to replace your system HDD with a SSD. You would clone your C:drive onto the SSD, then swap it out.
3. Disk imaging. This is a very similar process to cloning, with one important difference. The image of the data on the physical disk partition(s) you are backing up is moved to an image container file on a separate drive. This file cannot be installed as a working drive, until you use a restore process to write it back onto a physical drive.
Multiple images of different volumes can be archived in an external drive all in one partition. The simple way to organize them is to use a different folder for each backup job. So you start by creating one backup job for your C:
drive, decide how many version you wish to retain, and what path to use for the folder you want to use as the target.
Then create separate jobs for each remaining disk you want to image. If the drive is always connected, you can setup automatic schedules. If not, you can kick the jobs off manually when you wish to run them.
I am using Macrium Reflect, but many use Acronis in the same way as I have described.
Don't forget to create the rescue boot media that your imaging application offers, so that you can restore your system from a backup image if necessary!