I wanted to a quirky costume with my wife that now one else has been doing in the Mass Effect Universe. We chose to do Diana Allers with her floating camera bot. The plan was to have me hide in a black body suit and follow her with the camera.
Step 1. Get in "skin tight body suit shape." Thank you Sean T.
Step 2. I built a frame out of 1/8" plywood.
This got filled with the blue polystyrene foam. The chunks got sanded down and coated in gesso.
The gesso is supposed to prevent any reaction between the foam and the bondo that I was about slather on. It did a decent job, there was still some bubbling. After some sanding and filling, the bot was looking pretty smooth.
I made a custom bondo channeling tool to get the grooves to be nice and smooth. The bottom parts of the camera we built with pvc foam/pipes. The smaller camera is a series of wooden bits that I got at AC Moore.
Here is a shot of the camera bot in action. It was a really fun costume to play with. Most of the video I shot was of me poking people with the microphone.