http://www.yumestudio.it/angychan/tutorials/dress1/dress1.gif

Pixel shaded dress tutorial - image only, no text!

http://www.starfireresearch.com/as/

Has tutorials for skin, faces, and dresses all using tool shading in Photoshop or similar.

http://edge.atspace.org/tut_med_dress.html

Uses tool shading in such programs like Photoshop, Paint Shop Pro and The Gimp.

http://www.fainelloth.de/dress_tut_new.htm

The technique involves smudging and layers to acheive the effect. The tutorial uses Photoshop but you can also achieve the same desired effects using Paint Shop Pro or The Gimp.