Hello,
for this type of modelling you better use polygonal modeling and some subdivision technique Subd and/or Catmull&Clark. There are many examples here and with other tool.
The technique here is :
Make a rough shape with a mesh with quads
I use Catmull and Clark to have an organic shape, I move the result in order to see the result
Move face, point, edge of the mesh in order to change the shape. All the trick is to have enough faces to make what you want and not too much to keep the modelling simple.
It is also possible to use Rhino Wip Subd, but not mandatory. You could keep doing mesh modelling. And at the end make subd and then Brep.
I also use Bowerbird for waffle.
Starling is used to close the mesh for BB Waffle, so mandatory if no waffle !
I internalize the mesh I use, you will have to bake it in order to modify it.
metropol parasol Seville.gh (23.5 KB)
Happy modelling