careful scaling of the figure's parameters dials and the use of "magnets", which are a modifer present in Poser to change the shape. They also sometimes adjust the joint settings, but I don't think you'll go there often lol It just takes time and patience to tweak all those little settings. I've changed the title of my post here, hopefully it will get you the most accurate info possible ;)

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)