There are probably a couple philosophies as to how to handle matters, and with a laptop used as intended, more caution is needed. If it were me, of course, I'd be using a Linux environment and either encrypt the home directory or, even more likely, go with whole disk encryption, if I were worried about theft or my sensitive data. Irrespective of that, you still have to make sure you have access to your encrypted data in case the laptop (or desktop or whatever) itself fails. Lose your ability to access that data, and you're in a peck of trouble, regardless of your OS. Backing up is always important, and the security of those backups is important. If you're backing up to a physical space at home and are not worried about the security in storage because you're confident in your physical security, you can make matters a little simpler. If not, or if you're backing up into the cloud, then you've got the same issue and have to safeguard the backups with encryption.
For safeguarding a data backup, the simplest way, in my view, would be a tarball encrypted with GPG, which will not be platform sensitive. Just don't lose your private key; it will need to be properly safeguarded, too.