Hi mir4ea, that's going to be a pretty difficult project - the easiest type of stuff to do in NURBS is when you're able to work more using 2D curves, but for your project there with a lot of swoopy pieces and not many straight shapes you will need to be working with 3D swoopy curves more and that usually requires more experience to get used to.

The basic technique though would be to try and focus on each broad "sheet" of the object, you will end up building a surface (using Sweep, Loft, or Extrude depending on what happens to be easiest for the particular case) for each large sheet, and then trim those with one another to get common edges, then join those surfaces together and do a fillet to round off the sharp connecting edge.

The tricky part is that you often want to build your sheets initially as an extended shape and then the final outline only comes by trimming with other surfaces, rather than trying to model every single shape directly to an irregular outline. If you try to build surfaces directly to irregular outlines it's difficult for the shapes to be smooth and clean. So often times you need to kind of visualize the surface as a larger shape and let intersections produce the final outline.

So for example for this piece here:




You would build a sweep something like this to start with:



Then it will have the excess part cut off by intersecting it with another extended surface for the adjacent part.

- Michael