Twitter recently announced an updated layout that features an enlarged cover photo, similar to a Facebook Page or Google+ cover photo. For all my clients who plan to update your Twitter page to the latest design, I wanted to provide a Photoshop template for this cover photo, which is recommended to be 1500px wide by 450px tall. Hope it helps!
Download Twitter Cover Photo Photoshop Template
Note: The template contains a layer that estimates the location of your Twitter avatar image. You’ll need to hide this before exporting to web. I also recommend exporting to JPG, as PNG format would be too large of a file size, hurting page load time.