After some wonderful instruction and help from Familyman (can't thank him enough) I started my first ever costume build. It's a Cyberman only child size.
I started with pictures and a few sketches (again, thanks FM) and kinda winged it for the chest and back pieces.
First I started with paper to create a pattern for the chest/back bits and then used camping mat foam. I couldn't find the anti-fatigue mat until recently.
I cut the circle for the emblem and then a smaller circle to inset it. The "C" was cut out along with the brackets and assembled.
It took some eye-balling and then measuring from the middle to get it about right.
Then I had the the "bracket" looking detail on the chest area drawn on paper and added to the foam, taping each section beneath the other to get the 3-D effect.
Duct tape holds the front and back together at the moment. Next I plan on doing the sides and back parts.
wish me luck!
Here's a few pictures (not sure why some are rotated 90 - they look OK when I attach them):