There is quite a bit involved in optimizing a website to make it fast loading, while still having the content and functionality that you may need or want.
The first thing we will do is take a look at how your page loads, how long it takes, and what the bottlenecks are. You can do this yourself to get an idea of the performance of your site.
Typically we will achieve a Google Page Speed of 90% to 95%, and a YSlow grade around 90%, with initial load times under 3 seconds and subsequent (cached) hits rendering in around 1 second. For light-weight sites times can be around half of this. On existing sites, depending on your choices, results will vary.
The biggest single thing you can do to speed up page loading is to ensure that pages are being cached, thus avoiding the time it takes to run PHP code every time. Along with this, your .htaccess or web.config file needs to enable cache-control headers, thus enabling browsers to cache files. If these have not been done, then doing them can transform the performance of a site.
How to speed up WordPress web site load times
If you are using WordPress, you can install the best caching plugin there is — WP Super Cache — and watch your site start to fly. However, you will still need to add cache-control to your .htaccess or web.config file.
For WordPress users, the next most important area to look at is the use of plugins. They can seriously bog down a site, even with caching, because so many plugins load files that can interfere with a good loading sequence. Good plugins will avoid loading files, especially CSS, and will load JavaScipt in the footer, not the head of the page. This really makes a difference.