Your grapefruit juice is my caramel macchiato. I get what you mean, though, and this is roughly what I have in mind. Sit down at the beginning of the day, a large cup of hot coffee on my table, and get some hard work done. You're mostly right when you say that the creative part is done. I'm not looking for new plot-lines or fresh characterization. I need to sit down, read the whole thing, and edit it it for uniformity, tie it all together. This is a process that might require a bit of creativity, yes. But it mostly requires hours of unwavering focus and concentration. Rum does sound like a great reward though. Unfortunately, when it comes to rum I have a history of treating it as a pre-ward. Thanks for the advice.
If you are a morning person go for it in the morning. (I am a morning person.) If a night person, go for it in the night. Understand what your strengths are, how to manipulate yourself (so that you feel inclined to work), and play to them. When you go to edit it set yourself up so it is as easy as possible to do the work you want to do.