Good tips for Wordpress users. Another great option we went for is hosting your entire site/blog on S3/cloudfront. This can be done using tools like Jekyll (https://github.com/mojombo/jekyll) or Middleman (http://middlemanapp.com/).
If your site is entirely static content and mostly text, you don't really need a CDN. I've had a static site survive the HN frontpage without any problem on cheap-ass shared hosting.