An advertising agency that I work with on a fairly regular basis was given a project by DuPont. They were launching a web site, and they wanted to develop an interactive tutorial leading first-time visitors through the site.
Rather than simply creating a dull online manual, the art directors decided to make it look like a business presentation. Three fictitious characters would lead visitors through a series of slides explaining the various aspects of the site.
Setting up a photo shoot with each model in their exact positions in an actual theater would be impractical, costly and time-consuming. The decision was made to shoot each model in a studio in a variety of poses. The backgrounds would be removed from each shot, and the interactive designers could place the actors' images wherever they looked best.
I was brought into the project after the photo shoot. Since the photos were shot digitally, I was handed two CDs full of model photography. It was my job to remove the backgrounds, retouch out any imperfections, and color correct the photos.
Most of the originals were in pretty good shape. The photographer shot everything against a white backdrop, making it a lot easier to separate the models from their backgrounds. However, any furniture the figures were using (chairs, stools, etc.) also had to be removed.
For the Photoshop-savvy, I always use layer masks to knockout backgrounds. A lot of designers will use clipping paths, but that's a bad way to go, in my opinion. Clipping paths are imprecise, leave edges unnaturally sharp and are impossible to use with hair or other soft-edged objects. It's also convenient to have the object on its own layer in Photoshop for the addition of drop shadows, different backgrounds, etc.
After the models have been knocked out, my next step is to color correct each image. Each model must look like they are all in the same room with the same lighting conditions. Since the majority of the shots were a little darker than desired, I also had to brighten things up a bit overall.
After everything looks good, my last step is to convert each image to a 72-dpi PNG file, remembering to sharpen each file after they were downsampled. From there I delivered a CD-ROM full of retouched imagery to the interactive designers, where they built the final tutorials in Flash.
While this project had its own unique specs, the basic process can be applied to a variety of projects. A catalog designer may have four CDs full of furniture photography that needs to be knocked out. A photographer may consider providing layered Photoshop files to his or her clients as an additional service. There are a variety of ways that I can help a workflow, it's simply a matter of asking!