Hi Mala,

re:
> How can I make it better and smooth? Is it handcraft and feeling-modelling? Or are there given rules
> to make the form fine? Or automatic refining tools in moi?

Hi Mala yes it will be a matter of adjusting the control points of the curves you used for constructing the shape. There aren't any tools currently for doing that automatically.

Localized bumpy details can be awkward to model with a CAD modeling toolset, the main focus in CAD surfacing is on making broadly smooth sheets and not really on fine local bumpy details.

Bumpy shapes and fine tuning bumps can be done better in a displacement brush based modeling system like 3D Coat or ZBrush. Those allow you to refine bumpy details using brush strokes directly on the surface.

- Michael