Dmax can be applied SEVERAL different ways. Some are easier, while others are more effective. In my experience there really is no ONE way to dmax that works for every image. What you need to be familiar with are the reasons behind replacing CMY with K and then make the move with as little color shift as possible. This may require a different curve or technique for different images since some images have cool shadows while others have warm ones. I find that a lot of prepress shops use a profile conversion to get the dmax down, and with a less than adequate result in my opinion. If you just go to convert to profile>web coated it will drop the dmax enough for many applications. It also jacks up the rest of your colors in your image. A one percent shift in a midtone area is too much! They should be left untouched. There is also a layer set out there that you magically drag around from image to image and adjust the opacity of it to get the desired affect. This also is a little rookie in my mind since it doesn't leave you to figure out exactly what you need to do. Often it shifts the shadow hues also. Bad news!
How good of a retoucher are you? My studio is actually hiring at the moment and if you're truly a good catch I'd love to have you come check it out and take a quick photoshop test. If you're interested, we are better and more fun than a "prepress house". Drop me a line at email@example.com
. You can check our work out on our website as well if you like.
Hope all this helps.