This Instructable will show you how to make a suit out of cardboard, but probably not very well, since I only have pictures from after the suit was crafted, but here it is anyway.

Step 1: The Making: Straps Tip

On the straps for the leggings and vambraces, for which I used Duct Tape, make sure to put tape on both sides (double-sided tape as I call it), if you don't then the strap will just stick to your arm or leg.

Step 2: The Making: Torso Support

This will show you how to keep the torso armor from slipping off of you. I advise to measure yourself with the length of cardboard you will use for a strap to know how long it needs to be.