I use Shade3D ( commercial ) and Blender ( free ! ) for creating geometry - although my target use program is Poser, not DAZ Studio. I find both modelling programs quite good for mid-range complexity. I believe professional production studios would use a different range of products such as Houdini ( which is free for learners ) - I've had a go at that one as well, but the commercial price is out of range for individuals just starting out.

Eternal Hobbyist