What are you doing for your backups?

I've been "backing up" my distros and servers by just copy-pasting files to-and-from a hard-drive.

I've never done a back-up full enough that I could recover to a full install. This has worked for me since I've never actually come into a problem that I couldn't fix.

I'm wondering what everyone here does for backups? What is your use-case? (Work computer, personal laptop, server, etc?)