I back up both my DAW and my general purpose computer once a month on or shortly after the 1st (makes it easier to remember to actually do it by establishing such an obvious date). I use Acronis and make image copies written to external drives via USB 3. If it was USB 2, I doubt I'd be so regular - with USB 2, the backups would take all night to run. With USB 3, even my DAW which has tons of data, with massive amounts of Kontakt (and other) sample content, still only takes a little over an hour.
I keep the external drives in a fire-proof filing cabinet. Probably would be more risk adverse to store these somewhere else than my house, but ... well, I can't be bothered.