Here's another good tutorial from Princess Libra, for a very popular technique in clothing marketing -- the "invisible" person ... remove the human model from the clothes .... the Princess writes :
The way to learn the Clone Stamp tool (as well as adding a virtual drop shadow) is to create an invisible man or woman. We can transform an ordinary portrait or action shot to make the person disappear, leaving floating clothes around a space. Adding shadowed wrinkles also adds realism.
Preview of Final Results
Step 1
Open a photo of a person, preferably one that includes the entire body. Choose one with a simple background that can either be cut out or cloned for a more realistic look. For each step, work on a separate layer to reduce the risk of having to start over.
Open a photo of a person
Step 2: remove the human
Zoom in to the areas of the person where their skin is showing (Hold down the Cmd and then press + or - PC: Hold down the Ctrl and then press + or -).
Select the Clone Stamp tool and use it to erase the areas not too close to the clothing. To do this, hold down Option (PC: Alt) and click an area to clone, then release the key and click-and-drag over the area to paint, replacing the pixels with the source pixels.
If you have a completely solid background, just select the areas with a Selection tool and press Delete (MAC: Backspace).
Open a photo of a person
Step 3: reconstructing openings
Once the pixels behind the hands, feet and head that would normally be the background are replaced using the Clone Stamp tool or the Selection tool, we need to redraw what the inside of the clothes would look like. Using a Selection tool, draw around each area and fill it using the Paint Bucket tool. Rarely does a solid color look real, so add shadows by keeping the area selected and using a large, soft brush with the Brush tool, click-and-drag around the edges to create shadows for depth.
http://www.graphic-design.com/photoshop/tutorial/floating-clothes-photoshop