Sitting down is another can of worms altogether - you just found that out, I think. :-) Steve Shanks has used an interesting technique on a couple of PoserWorld long dresses, though I haven't got around to trying it myself. The skirt is split into hip, rThigh and rShin - no left hand parts at all. This is fine for a tight skirt - she sits down, the skirt conforms to her right leg, and you just need to tweak the dress and/or her left leg until it all fits. If you wanted a stretch fabric effect, then some morphs would be needed.