Fred
Backing up the entire HD is the best method. This way if you contract a virus or ransomware or other malware or if your HD fails, you can restore your backup and be back in operation in about half an hour.
There are a couple of ways to backup- the cloud (which usually costs) or locally to another hard drive. Now the question is what software to use- free or paid.
My method is to back up the entire HD to another HD using Acronis True Image (paid). There is also free software to do this.
http://www.techradar.com/news/the-best-free-pc-backup-software
EDIT: If you sync your files and then get hit with ransomware, the synched files will also be encrypted.
Tracy L
I use a WD USB drive with WD backup. If you want an online service Carbonite is fine. If you want a cheaper system just use ONEDRIVE or DROPBOX and sync your documents folder. https://www.windowscentral.com/9-tips-help-you-fix-onedrive-sync-problems-windows-10