High performance websites tips for faster pages loading

There are 14 common-sense tips to boost your website performance whether it was a Drupal site, or else.
1. Make fewer HTTP requests

* image maps
* css sprits
* inline images
* combined scripts, combined stylesheets

2. Use CDN
3. Add an expires headers
4. Gzip components (scripts, stylesheets, XML, JSON, images, PDFs)
5. Put CSS at the top, use link (not @import)
6. Move scripts to the bottom
7. Avoid CSS expressions
8. Make JS and CSS external (inline cause bigger HTML file, external causes extra HTTP requests BUT cached)
9. Reduce DNS lookup
10. Minify Javascripts
11. Avoid Redirects
12. Remove duplicate scripts
13. Turn off ETags
14. Make AJAX cacheable and minified