oh, and here's another piece of information that makes me think you're supposed to just lay decorated parts on top:

Quote - These are usually items sitting on another cloth group and have only passive movement, either following underlying body movement or other parts of the cloth.

i haven't put it to test yet, though.  LaurieA, you've certainly worked more with ribbons than i have.

oh, and i don't do box modeling or NURBs and splines in general.  i mean, i think i need to learn more about NURBS because they make a nice regular surface, but i use a highly altered version of the tutorial by Adorana at RDNA.  i converted her methodology to Blender.  i'm also not nearly as wed to using the exact process a seamstress would, but i'm pretty conscious of how the clothes are actually built.  between thinking about  modeling and creating dynamic groups in terms of how clothes should actually work and using Blender's cloth dynamics to build the clothes, i get pretty good results.  i wish i understood more about how to control stretching in Blender's cloth, but all in all, i'm pretty pleased with the results.