Prop I think would be best for something small like a necklace. A figure could conform if it were something like a body necklace (going from the nexk to the legs or something, that way it flows along the body the whole time). Props are small, efficient and don't need to be conformed or what-have-you. Remember with props, extract the geometry from the prop file and have the .pp2 (prop file) call the .obj (object file) for the prop. Also, parent the prop before saving it, that way it will automatically be smart-propped to an area... say the neck, for a necklace. Anyone can use the dials to adjust positions if they need to. If possible, try to parent it to a standard barebones figure as it loads in at default. That will require the least amount of adjustments from people that use your props. Conforming figures don't need to be positioned just-right to make them work, but again, something simple like earrings or a necklace (in their purest sense) don't make good conforming figures. I guess an example of making something a conforming figure is Kozaburo's popular MK3 Hair. It comes as "hair" and "figure". The figure could be conformed so that it automatically zaps to the top of Vicky's head and when you move the left shoulder, her hair that hangs on that side would move along with it. That's a good example of deciding whether to make something conforming or not. Although I believe the hair does not perform as that, if memory serves me correctly.