Here’s a few basic rules to improve the performance of your website. Perhaps in the future I’ll go deeper into this topic and cover some more advanced topics.
1. Minimize HTTP Requests
2. Use a Content Delivery Network
3. Add an Expires or a Cache-Control Header
4. Gzip Components
5. Put Stylesheets at the Top
6. Put Scripts at the Bottom
7. Avoid CSS Expressions
8. Make JavaScript and CSS External
9. Reduce DNS Lookups
10. Minify JavaScript and CSS
11. Avoid Redirects
12. Remove Duplicate Scripts/Code
13. Configure ETags
14. Make Ajax Cacheable
15. Flush the Buffer Early
16. Use GET for AJAX Requests
17. Post-load Components
18. Preload Components
19. Reduce the Number of DOM Elements
20. Split Components Across Domains
21. Minimize the Number of iframes
22. No 404s
23. Reduce Cookie Size
24. Use Cookie-free Domains for Components
25. Minimize DOM Access
26. Develop Smart Event Handlers
27. Choose over @import
28. Avoid Filters
29. Optimize Images
30. Optimize CSS Sprites
31. Keep Components under 25K
32. Pack Components into a Multipart Document
33. Make favicon.ico Small and Cacheable
34. Caching strategies like using Memcached
35. Serve resources from a consistent URL