Different variants of Ransomware are being created, making the process of securing your data difficult. As long as you have information on a device that is on a network interface, it can be compromised. You can follow the trends to protect your data from previous ransomware, but there will always be a new variant.
The safest way of data protection is to simply inform yourself of where you are going and what you are downloading. Never go to sketchy websites or let someone in the back-end of your computer through remote desktop applications like TeamViewer, RealVNC, LogMeIn, etc. Don't click on spam links in emails. Sometimes even the unsubscribe button at the bottom of emails can be a phishing scam. Never do business with someone that you can not physically track.
Pertaining to the data that is very important but only beneficial in your hands alone, always create a physical backup. Cloud storage has proved reliable for some time, but it too can be compromised.
This is about damage control. Nobody can predict how invasive some of the malware will be. Just like investing, don't risk anything that you aren't prepared to lose. Back it up!