Recently I have been exploring way in which to make Magento fly, and when I say fly I just mean not be as sluggish as it is out of the box. It’s well know that Magento is resource intensive meaning that a good powerful server is a must.
As far as hosting goes my default option is and always has been Simple Servers. Not only have I found them to be the fastest Magento hosting but also their support and response time is very impressive.
Another must is a well configured .htaccess file, this is normally a very quick win if it has never been set up. You can find the version that I prefer to use here.
CSS, JS and HTML compression
To merge CSS and JS files:
System -> configuration -> developer
Merge CSS files -> yes