The past episodes of the Christmas Calendar has been on a start tutorial, but we'll need some goodies for longtime umbracians as well.
Today is a little easy gem that will make the umbraco admin interface seem much faster - and best of all it'll take a couple of minutes.
umbraco uses quite a number of files to serve it's neat UI. From html to images, css and javascript an umbraco user with full access to the admin UI can quickly download more than a 100 files at the first few page clicks. Now even though these files are tiny (most of them around 2-3kb), IE can only serve 2 files at the time, making the initial start of umbraco as well as opening an editing page seem very slow.
The tricks is to add cache headers in IIS and it's drop dead simple to do. Open up IIS and locate your site. Then right click the "/umbraco_client" folder, select properties and choose the "HTTP Headers" tab. Check the "Enable content expiration" and set "Expire after 7 days":
You can do the same for "/umbraco/images" and "/umbraco/js" as well.
The performance increase will be significant for your users and they'll love it. However, when planning an upgrade that involves changes to the caches directories (3.1 will), remember to set it back to just one day and then do the upgrade afterwards (that way you're sure you won't have any cache coherency issues with the files/js in umbraco).