Just a heads up, I'm doing a very similar build (ODST helmet fully loaded and the Collar/Breacher), which is wonderful news for you.
Make sure you check out this thread for your build:
http://www.405th.com/showthread.php/28023-Official-Halo-Reach-Reference-Thread-*Pic-Heavy-Spoilers*/
Scroll through all the pages you might see something you like.
Make sure you also check out this post in the thread:
http://www.405th.com/showthread.php...eavy-Spoilers*?p=701493&viewfull=1#post701493
It has LOTS of pictures showing off the Collar/Breacher as well as some of the fine details of the LEDs and undersuit.
Oh, and it looks like your UA Forehead mounted attachment is upside-down.
To make it easy, look at the 4 protrusions on the front surface. The top two are closer to one another and the bottom two are further apart.
I mean, I'm sure you haven't "mounted" it yet, but I wanted to make sure you noticed it before you do.
Also, it appears as though you are using a Hugh Holder ODST helmet model to which I must say cheers!
They are my favorite for sure.
They do have one drawback though... they are VERY narrow.
Sooo I got some bad news. I tried my helmet on fully built. It doesn't fit and my ears get in the way and my head is to wide.
Sorry I didn't catch this sooner. I definitely would have said something had I known what model you were using.
ok I am having issue with making the vents on the helmet near the chin section.
Those 4 vents (2 on either side of the jaw) would be best made from craft foam.
In Hugh Holder's model, there are the pieces that don't really attach to other ones, which include those and the things that look like straps that come up from the bottom onto the sides of the helmet by the ears. These "floating surfaces" are meant to be made from thin-ish foam.
As for your visor, there are a few methods of approach. There is the vacuform method you could use, or there is this tutorial:
http://www.405th.com/showthread.php/30968-Tutorial-ODST-Visors-(and-other-useful-info)