Mostly by leveraging combinations of the following:
That being said, I believe that the best backups are the ones that involve minimal but regular user interaction. Just as you close up a storefront an hour before you go home at night so that you can zero out a register & clean up the place, so must it be habitual that you interact with the backup process.
To some people that means swapping out tapes or kicking off the process. To others it means checking the logs of the automated process to make sure everything completed properly.
What matters is that it matters. Pure automation alone will eventually fail for some reason and be unnoticed. Then you continue to run for a time without a backup - until you either catch the problem or else you have a real failure & no way to fix it.
I'm also in the habit of putting working files on USB drives to bring back & forth from home & the office, to keep files I'm working on in sync. If I forget, I usually SCP them over. So my home system becomes an off-site backup.
By no means perfect, but far better than nothing.
Wait! This isn't a Parachute, this is a Backpack!