Nosferatu,
All kidding aside, it might help if you explained your question in a bit more detail. Using conventional artist’s paints, an artist can paint a nude and then apply clothing and that is a time-tested technique, which can also be used in Photoshop using Photoshop’s painting tools.
However, many of us are not very good at figure drawing, and need some help. Photoshop can be used in conjunction with a 3D program like Poser from Curious Labs <
http://www.curiouslabs.com/> to do something much like what you describe.
There are tutorials on Modeling in Poser, Creating a UV Map and Using photos and painting in Photoshop <
http://www.infinitee-designs.com/Portrait_Tutorial.htm> and Compositing Images using Poser and Photoshop <
http://www.robinwood.com/Catalog/Technical/PoserTuts/PoserPa ges/SuperimpositionStart.html>.
Poser has a lot of third party support from vendors like DAZ Productions <
http://www.daz3d.com/>, Poser World <
http://www.poserworld.com/>, and Hand Span Studios <
http://www.handspanstudios.com/characters.html>. There are many other sources of support for Poser users.
There are other applications besides Photoshop and Poser that let you paint directly on 3D models (including beautiful female models), such as Body Paint 3D from Maxon <
http://maxon.net/pages/products/bodypaint3d/bp3d_r2/bp3d_2_e .html>. I have done a little experimenting with Photoshop and the much less expensive TrU-V from Texture Tools <
http://www.texturetools.com/TrUV.asp> to use Photoshop to paint on LightWave 3D models. There are more expensive solutions such as Right Hemisphere’s Deep Paint <
http://www.curiouslabs.com/article/productlist/74/>.
— Burton — (not associated with any vendor mentioned or linked to)