Using Cloudflare & recommended settings
Unlike traditional CDNs, Cloudflare is a proxy. You don't have to turn on CDN in FlyingPress settings.
Cloudflare CDN will be activated on your site as soon as you enable 'Proxy' in the DNS settings (orange badge).
Set Browser Cache TTL
Set browser cache to 1 year under Caching -> Configuration.
NOTE: Set 'Browser Cache TTL' to 'Respect Existing Headers' if you're caching pages in Cloudflare.
Turn on Auto Minify for CSS and JS files.
Turn off Rocket Loader
Though it might work in some sites, we highly recommend to turn off Rocket Loader.