I've started so many helmets, but never finished them, and through trial and error i've found a good way of getting the iron man helmet quite good. it was also very cheap, i think i spent around $3 in total and what was on spray paint :)
Step 1: Getting the Shape
what better way to shape the helmet for your head, than by using your head.
I used a plastic bag.
I wrapped it around my head (but cut the face mask out, so I could breathe)
After the plastic bag is securely wrapped around your head and take the shape of your head, have a friend cover your head in duct tape. to secure the shape.
sorry, but I didn't take any pictures of the helmet with duct tape round, but once you've done that, simply paper mache it all over
you must also add the circle things on the side of his head when you paper mache. those are optional tho
Step 2: The Face Mask
i'm not gunna lie, i made the face mask using someone else design :(
its really good and works
I didn't bother with the lights and stuff
Step 3: Painting
I used spray paint because its more shiny and it gives out a smoother finish
once painted and dryed, add detail with pen. you could do what you want with the design.
on the back i attached a bit of card (inside or out) which will seal the helmet making it a complete helmet.
Step 4: Last Touches
To connect the face mask to the helmet part i used velcrow, as then it would be removable.
i also attached velcrow to the card at the back which seals the helmet.
Step 5: All Finished
Now all you have to do is wear the helmet with style :) impress people at costume parties