On the ClearCode blog today there's a new post for the Synfomy2 users out there with some recommendations about taming your project to make it more manageable and maintainable.
When managing projects based on Symfony2, from the technical side, it is a good idea to establish a set of rules for the project. If you haven't established and implemented such rules yet, then they should be created as soon as possible. Why? Well, no matter how many people are working on the project, the code needs to look like it was written by one person. [...] Symfony documentation doesn't specifically focus on this issue, and the bundles that are written by the community have their own set of rules. [...] Learning from mistakes as you go along cannot only be costly, but also time consuming. It is good to have a starting point, something that at least has worked for someone else. This is how the idea to share the guidelines on the Taming Symfony Project came about.
They list out some of the guidelines of the project centered around various aspects of the implementation and the directory structure. They also talk about standards around the use of Doctrine, Twig and Services.