For all of those on the free plan, I HIGHLY suggest upgrading to the PRO plan and taking FULL use of the WAF Firewall AND setting up HSTS under the SSL/TLS app.
My websites and servers have always been very secure, but I had no idea just how much the WAF firewall blocks or challenges once it is enabled.
For only $20/month, it is a HUGE value for extra peace of mind!
Cloudflare is awesome!!!
ps: Great place to check your website security: