Reduce the loading time of website

Following are IMP Rules to Reduce the loading time of website

1 - Make Fewer HTTP Requests (means Less Ajax Call)

2 - Use a Content Delivery Network (CDN)

3 - Add an Expires Header
    http://stackoverflow.com/questions/4603076/add-expire-headers-in-php-cant-make-it-work

4 - Gzip Components
    http://betterexplained.com/articles/how-to-optimize-your-site-with-gzip-compression/

5 - Put Stylesheets at the Top (CSS Files in head tag) 

6 - Put Scripts at the Bottom (Js files in footer)

7 - Avoid CSS Expressions (e.g 100/2)

8 - Make JavaScript and CSS External (Store the Css /Js in file and include them)
    http://developer.yahoo.com/blogs/ydn/high-performance-sites-rule-8-javascript-css-external-7205.html

9 - Reduce DNS Lookups
    http://developer.yahoo.com/blogs/ydn/high-performance-sites-rule-9-reduce-dns-lookups-7207.html

10 - Minify JavaScript and css files (remove space, tab, indentation etc)

11 - Avoid Redirects (remove un-necessary redirect) 

12 - Remove Duplicate Scripts(Adding same javaScript / Css files two times)

13 - Configure ETags

14 - Make AJAX Cacheable

15 - Use Server side caching

16 - Use Client side caching

17 - Run time javaScript load must use cache