The image appearance compared to the digital version is one thing that is currently confusing me - I have a colour managed, brightness balanced monitor calibrated every couple of weeks and using printer profiles supplied by the paper manufacturer using printed examples I sent to them. So it's as accurate as it possibly can be... yet STILL something isn't coming out quite right!
OK, you are definitely on the right lines in what you are doing. Other than images coming out too dark, are there any other issues such as colours being inaccurate?