How to speed up page load of WP site and link comfirmation of a tutoria

I'm so pressed by my client to speed up his WP site using Revslider, and Jetpack as major Plugins. I configured WP Super Cache but seems not enough for the low internet connectivity used by many Africa/Nigerian community except those that invested into 4G hot spot modem. Is there any cost effective ways aside premium CDN to make the site speed load faster like sonic speed? In addition, I've used WP3 Total Cache and that disfigured the site (CSS not seen). What can I do to make this site load faster for a low connectivity internet user group (mobile user inclusive)?
In fact my client was so adamant to use this tip her: and I'm wondering if it can be use on WP site?