I am trying to improve my surface modelling skills by attempting to produce a CAD (near) replica of my bicycle helmet. 

Creating the shapes seems very difficult. I was wondering if anyone had an advice on how to make these swooping streamline features/intersections. Evan after these have been made I also need to add/include draft angles on all of the foam parts!

I have attached some photos of my bike helmet as well some screen shots of my current attempt.

You can see that my attempt is still quite block like an bulky compared to a elegant product. My design also lacks draft and has far fewer features.

My basic attempts so far have been:

Concept 1)
Create a basic outside cap boundary surface (Surface A)
Offset Surface A inside by 4mm to make Surface B
On top plan sketch some curves and split through Surface A
On top plan sketch some different curves and split through Surface B
Thicken all surfaces and merge

Concept 2)
Create projected curves for every swooping line/corner
Fill surfaces between these lines
Try to create solids once all surfaces a merged

It just seems to take forever!!

Any help??