One of the best ways to improve the performance of your website is by letting a CDN service handle some of the load. MaxCDN, CloudFiles, and CloudFront are all service you can take advantage of to speed up your website. Thanks to CDN Sync Tool, you can speed up your website while having your static files synced with the above mentioned services.
CDN Sync Tool is not perfect but worth testing if you rely on CDNs to speed up your site. This is a free plugin.