It looks quite good!

I think a personal preference for me would be to "meld" those attachments on the sides and top of the helmet into the actual helmet, so it looks like it was made from one piece of metal and not like they were glued on... I hope you know what I mean, lol.

I haven't tried my hand at any modelling myself though, so I'm not sure if that makes it a lot more complicated.

Another idea could be to make the sides into loose hanging chainmail or maybe just overlapping plates to break up the monotony of a single helmet piece. It depends what kind of helmet you're trying to create though, if it's a sci-fi helmet then that idea would be bad.

It does have kind of a 70's Flash Gordon look to it hehe, very promising :)