Here is a Renaisance drapery study by Durer. We used to set up drape studdies and draw/paint them over and over back in school studing classical paintiung.

There is an other trick when it comes to doing folds without a drapery model to work from for Poser post-work... it has to do with the folds in the robes in Medieval art... cainery (sp?)  folds but I can't remember the spelling.

Medeival and early "proto" Renaisance art featured conventions for depicting volume and space which were pictoral or schematic rather than optical... shading that was based on volume rather than incident lighting, lighting that was all-over (light of God) rather than projected from a source, and cloth folds that were schematic rather than observed.

Cainaery folds were so-calledby art historians because they were an abstract schema for creating the illusion of draped cloth based on the shape of chains supended from either end... they followed the curve made by such a chain hanging from two points. The folds were created by imagining two fixed points of tension where the cloth was held fast to the structure of the body underneath (maybe by a closure or a bone such as at the shoulder or knee) and "hanging" the folds between these points represented by the dark inset cloth alternating in horizontal or vertical bands with the light projecting cloth.

With Poser this applies when you look for the "fixed" points of the cloth on the figure and simulate folds with theses light/dark bands hanging from these points to imply both the dimensionality of the folds and the draping effect of gravity pulling on these folds... they will curve down at the point between the fixed points and the bands will be softer and broader while at the fixed points such as at the bent joints the bands become narrow and compressed as well as sharper... like "crows feet" at the corner of someone's eyes when they smile.