Never forget the overheads!
While writing the proposal, one aspect you should pay particular attention to is the correct estimate of the time budget including the overheads. These depend on the instrument and strategy you intend to use in your observations. If you underestimate the overheads at the proposal writing stage, you will pay for their cost later. Indeed, the telescope time approved by the ESO panels will correspond to the total time allocated to your proposal. If you underestimate the overheads at this stage, this will necessarily imply reducing the exposure time when preparing your observation.
To properly estimate the overheads you can use the tool p2demo. This is a version of the software p2 to be used to prepare the observations in Phase 2. p2demo contains tutorial folders for each instrument and each observing mode. You can use the template OB suited to your project to have a look at the real overheads, clearly indicated in the tool.
Be aware that many users take advantage of this tool to get familiar with p2. Thus, you will find in each run not only the tutorial folder but also many user folders. We recommend to delete the folder with your experiments after you finish practicing with p2demo.