I use Macrium Reflect to back up my System disk, which contains the O/S, apps. I keep user data off this drive, such as MyDocs, email, etc. This is configured to create multi generational back ups circa 6am every morning. When I wake up I have a confirmation email telling me that my backup is successful. A full backup happens every Sun morning and incremental backups Mon to Sat. Works a dream…Set and forget.
I also use Macrium Reflect to backup my internal Ssd. This contains my vip data, incl images for the last 18 months, emails, docs, spreadsheets, presentations, databases and my Lr catalog. As per my system drive, multi generation backups are taken, with full backups early on a Sunday morning and incremental backups each day from Mon to Sat. Again, I wake up to an email confirming these backups have been successful.
I use Beyond Compare to synch my legacy images from a spinning disk to a second backup internal spinning disk and a lan based Nas drive. I like Beyond Compare due to the intuitive nature of its GUI interface, which gives a very good view of the status of big synch operations.
I would use Chronosynch if I wanted to schedule this task and just operate in the background, Beyond Compare does not have a good built in scheduling tool.
Using these tools, my system drives are backed up in a manner than my operating systems and apps can be recovered to exactly how they were configured yesterday, I have all my personal data backed up, Lr Catalogs and all my images.
Any backup process dependent on manual operations is ultimately doomed to disaster. Take note of the comment above that your target backup device should be large enough to backup all of your data.
You will note the seriousness of the advice give above, gleaned from years of hard earned experience.
I once had to rebuild a system disk… due to a disk crash. While reinstalling a new drive and operating system was a pain, I totally underestimated the effort required to reinstall all the apps that I was using and reconfigure them again to reflect many years of fine tuning my Microsoft, Adobe, CAD and other systems.
While I mention Macrium Reflect, Beyond Compare, Chronosynch, etc…. I am not pushing these products. There are lots of good options available.