After the mega feature enhancements that we added to Style Sheet in 4.3, we have been getting an awful lot of support requests and mails asking for examples to do all sorts of stuff. As a direct consequence, I have added tons of new documentation. What's cool is that there is a separate example for styling each and every widget in the Customizing Specific Widgets section. Previously, the documentation was one flat html file. But it grew so big that our doc team has now split it up into separate pages. Trivia question: Which is the biggest documentation manual in Qt ? :).
My favorite bit is the Customizing TreeView example. One can style the tree view branches with 5 images. If you don't like the tree view lines, you need only two. Here's how it looks: