I've been working all day on printing. I'm mostly working from old negatives that I never made prints of. And I keep learning new tricks. For example: ImagePrint suggests that 240 PPI is fine for the print and that they interpolate it up to 360 before sending it off to the printer to do it's thing at 1440. There is a difference, especially in the darkest areas (at least with my workflow). So I'm re-doing prints at 360 PPI so there is no interpolation.
My workflow for black and white is something like this:
1) Scan the 35mm negative in at 5400 PPI. (Remember to use the grain dissolver on the 5400). Do enough with the scanner software so that you are not dropping any information that is in the negative.
2) With the soft-proof option set to the Epson Matte Paper, jump into Power Retouche B&W Studio. This is where you really get a lot of control over the tonal quality of the print. Save your Power Retouche settings for each print you do so you can apply them to various sizes.
3) Save a new file at 360 PPI at the size you plan to print.
4) Back into Power Retouche to use its sharpening tool. Save that file.
5) Into ImagePrint. I'm generally using the "gray profiles" which gives you a bit of control over the warmth or coolness of the print. Write down the settings you used.
6) Print on Epson Enhanced Matte.
7) Then there is a series of prints - undoing the sharpening - making further tonal corrections - reapplying the mask etc. until you have a print you are happy with.
8) Bring out the Hahnemuhle PhotoRag 308 paper. Set ImagePrint profiles to use this paper.
9) Hopefully by this point there is not too much back and forth since this paper is so expensive.
10) Let the print sit overnight and then review it again the next day.
All of this is done in grayscale. The file needs to be in grayscale to work with the ImagePrint "gray" profiles which I've had the best results from.
Getting a pleasing print can be anywhere from an hour to a few days. I can get an acceptable print - usually the first time out. What takes time is fine-tuning some small area that I find annoying, or seeing something when I go up to a larger size that I didn't see in the smaller proof version. I find that I have to be most carefull with the pure blacks. They need to just be on the edge - say between 5 & 10 in the levels box, or else they get a muddy look. Things like specular highlights seem much easier to deal with, and middle-tones are the easiest. There is no color shift when working with the "gray" profiles in ImagePrint unless you use the wrong profile, which I did once and then I got a mess of weird results. What is great, is that I am thoroughly enjoying the printmaking process (something I loathed in the darkroom days).
One other surprise: usually the files that began life as color digital files from the D300 are the easiest to manipulate. First off, there is no dust or scratches to deal with. But more important, the use of various color filters in the Retouche Black and White Studio makes it easier to do things like darken skies, or lighten greens etc. This stuff can be done in Photoshop without the filters but it often involves masking which is still a pain for me, though I'm getting better at it.