your original problem might be that the shape that comes with the character you start from might not be great for the things you want to achieve, so you might want to turn down or even zero the slider on that body shaping morph. or mix with body sliders of other characters. (mixing different bodies can have horrible results too though.)
on the question itself, it depends on the morphs you've installed. but I often do some tweaking with hip size and hip bone size. also voluptuous morph has a breast filter which also gives more room to work (in case problem is that cranking up voluptuous for ass happens to make tits weird for that character).
a hint of pregnancy morph can also give you hip/belly shapes you want, as most of the characters have an unnaturally flat stomach.
in the end all of these tips boil down to the same thing: you just need to mix and tweak the sliders for that specific area and hope you find something you like. most morphs don't look quite the same on different characters, because there's other morphs affecting the same polygons.
