Minify CSS files
Use a tool like YUI Compressor to remove unnecessary spaces and line breaks. Google’s Apache mod_pagespeed can also automate this operation.
Minimize the use of SSL certificates
Only use SSL certificates for sections and services where they are truly needed. This is because encrypting all of the HTTP data stream requires a large number of CPU power. And so encrypting a page’s static elements such as images (except the content) uses up considerable resources while presenting no benefits.