Tony that example you refer to already has some really bad photoshop work done to it. Im guessing what they are looking for is how to achieve that look but properly executed.
The image is in B+W, which makes it easier already, they also have the pattern which could be handy. Removing some folds to simplify, leaving some less dramatic folds to keep the natural flow of the fabric.
They are looking for help, and this is how i would approach a clothing pattern problem 90% of the time. I feel very confident i could produce something realistic.
I have a firm belief that jobs like this are not impossible, it just takes skill and time, obviously time can be the problem. but as Klev says, its about not overdoing it.
The best retouching shouldn't be noticed.