My extra layer of protection is Linux. All my online activities like web browsing, emails, downloading... are done in a virtual machine running either Linux Mint 18 or Fedora 24. So it's pretty much impossible for my system to catch some ransomware. And if somehow my system gets infected nonetheless I've got backups.
Ransomware is only a threat to careless people who are too lazy to make backups or to people who don't have the knowledge to deal with this kind of threat. But that's in fact the case with all kind of malware.