APPROPRIATENESS
Every deliverable has an intended audience. The audience will determine the nature of the deliverable, how it is delivered, and the level of detail that is included. As UXers, we are great at thinking about end users but not so good at thinking about stakeholders within our project and what their needs might be from our deliverables.
We can also be guilty of getting carried away with the deliverables we produce. A deliverable such as a report or set of personas should meet its intended purpose and allow you to move on within a project and nothing else.