In spite of this, for some clothes, quads ended up with nicer drapes for me than tris did. Sometimes tris look better. Note that these were straight triangles. I haven't worked much with uneven tris because Wings doesn't have much support for it.

What is really important to me, possibly most important is how the clothing is modelled, and where. For collars, seams etc, you want to give them surfaces that outline their shape, which will enable the clothing to drape more realistically. It also makes it much easier to texture the UV map later. Say you have a shirt, you don't want tris or quads crossing over where the seams go. Make sure the seams go where they should, so they can bend properly there. :)