Encrypt your devices (computers and mobiles that support encryption) as this helps to keep your information and device safe in the event that someone gets ahold of your devices since it essentially scrambles the data on your device and will only unscrmble that data once a password / passphrash that’s (hopefully) only known by you is entered.
Defending against ransomware:
Ransomware like Cryptolocker can be harmful to individuals and companies alike. Some companies have paid alot of money in ransom due to these types of malicious softwares. You can find out more info and help about decrypting your files here