When a project goes well and everyone is happy there are still several critical things to do. These involve closing out any accounts that are project-specific, especially internal budget line items that can easily be forgotten, getting an official sign off that the project is complete and the product delivered, collecting feedback both internal and external, and most importantly the PARTY! And I'm serious about the party, even a small ritual such as donuts or pizza helps to close out a project emotionally and build a sense of community and teamwork that helps with future projects.