There are also some changes you can make to your portal-ext.properties file once you are in a production environment.
Set the following to false to disable checking the last modified date on server side CSS and JavaScript:
last.modified.check=false
Set this property to true to load the theme's merged CSS files for faster loading for production. By default, it is set to false for easier debugging for development. You can also disable fast loading by setting the URL parameter css_fast_load to 0.
theme.css.fast.load=true
Set this property to true to load the combined JavaScript files from the property javascript.files into one compacted file for faster loading for production. By default, it is set to false for easier debugging for development. You can also disable fast loading by setting the URL parameter js_fast_load to 0.
javascript.fast.load=true
Also, set the following parameters:
portlet.css.enabled=false
velocity.engine.resource.manager.cache.enabled=true
com.liferay.portal.servlet.filters.layoutcache.LayoutCacheFilter=true