Here's a list which are recommendated for improving front-end performance of a website:
The Exceptional Performance team has identified a number of best practices for making web pages fast inYahoo. The list includes 34 best practices divided into 7 categories.
1. Page Content
- Make Fewer HTTP RequestsReduce
- DNS Lookups
- Avoid Redirects
- Make Ajax Cacheable
- Post-load Components
- Preload Components
- Reduce the Number of DOM Elements
- Split Components Across Domains
- Minimize the Number of iframes
- No 404s
2. Server Operation
- Use a Content Delivery Network
- Add an Expires or a Cache-Control Header
- Gzip Components
- Configure ETags
- Flush the Buffer Early
- Use GET for AJAX Requests
3. Cookies
- Reduce Cookie Size
- Use Cookie-free Domains for Components
4. CSS
- Put Stylesheets at the Top
- Avoid CSS Expressions
- Make JavaScript and CSS External
- Minify JavaScript and CSS
- Choose <link> over @import
- Avoid Filters
5. Java Script
- Put Scripts at the Bottom
- Make JavaScript and CSS External
- Minify JavaScript and CSS
- Remove Duplicate Scripts
- Minimize DOM Access
- Develop Smart Event Handlers
6. Images
- Optimize Images
- Optimize CSS Sprites
- Don't Scale Images in HTML
- Make favicon.ico Small and Cacheable
7. Mobile
- Keep Components under 25K
- Pack Components into a Multipart Document
I got this short list from the book "OReilly High Performance Web Sites" by Steve Souders, Chief Performance Yahoo. Download ebook here.
Happy Programming!!!