All my computers have a built in data drive where 98% of our files are stored. Pictures, PDF and documents. My DAW is set up the same way. All Projects/ Audio is in the E drive. I back up before I shut down with a SAVE AS to the F drive.
For all my computers ( 5) At least once a month I back everything up to a external drive with plain old drag and drop.
All computers C drives are also partitioned and things like movies and music go there as they are easily restored from other external drives. ( I have a few)
So my method while not very sophisticated still has everything in multiples.
A new thing for the last year is I save all my work documents and files to Drop Box.
I love the way I can use any of my 3 computers and there they all are updated and quickly accessible.
Once a month I pull the SD cards from our 2 cameras and dump them into at least 3 computers. Then they are also backed up to the external. I also will dump them to my son and daughters computers and they do the same with us.
We never erase the cards now. We pull them once a year and put them away. Cards cost less than a roll of 20 film used to, so why re use them? Now I have to add the damn phones to this routine.
I have a collection of C and E drives from every computer I ever owned since 2000. I used to upgrade every year as drives were growing quickly back then, First drive was 10 GB as example. Last couple are 250GB. Anyhow there is at least 15 of them including old DAWs.