Elements of the helmet that I will try to incorporate into my model.
Hachi (helmet bowl)
Shikoro (neck guard)
Tatemono or datemono (helmet crests)
Fukigaeshi (wing- or ear-like projections on both sides of the kabuto)
Mabizashi (brim or visor)
Shinobi-no-o: Kabuto would be secured to the head by a chin cord (shinobi-no-o)
Ukebari (hachi lining
Link to more information.
Step 2: Worbla Thermoplastic
Use hot air, water or steam (min 200°F) to bring this plastic to the shape you want to (heatgun recommended). The material can be heat-formed even after repeated cooling, it is safe to use and solvent-free. Unlike other heat-formable plastics, Worbla leftovers can be molded and shaped like clay, so there is almost no waste. Worbla hardens very fast and can be sanded. The extra glue coating on the shiny side makes it very easy to attach several layers by heating up the pieces, as well as attaching additional components. Start with a thin sheet then build up, or create sturdy pieces with multiple layers from the start."
Link to where I got my thermoplastic.
Step 3: How to get the correct shapes.
Step 5: How to reshape Thermoplastic.
Link to a shaping tutorial.