We get a lot of questions about rigging with ZIVA VFX that stem from a misunderstanding about how to work with physical simulations. As much as possible, think of the rig like a real physical deformable object. I like to use the analogy of a 'meat puppet'. How would you build a puppet for your character, in the real world, out of meat, gelatin, and other elastic materials? Which material would you choose for which parts? Where and how would you attach those together? Whatever you would do in the physical world is what you should aim to be doing with the simulated rig. This line of thinking builds the most reliable and realistic results.
Unfortunately, one is often forced to compromise from that principled position due to the limitations of the simulation or the limitations of ones schedule. Nonetheless, that is the correct foundation for thinking and reasoning about Ziva rigs and for choosing when and how to compromise. Part of the learning curve for ZIVA VFX is learning how to get the solver to act as physically as possible within your computer budget (e.g. tuning resolution, time-steps, collision detection, etc), and recognizing when you won't be able to get the physical result from Ziva and need to compromise with non-physical techniques.