So once I had my Clay Bumble I covered him with thin strips of masking tape and using a fine tip sharpie drew out my patterns (like dress making) and you only need to do one side cause you can just flip your patterns to get the other side. the little marks are to help line things up. At that point I took my exacto and carefully cut each pattern off and taped it to a piece of card stock. I then scanned the card stock into a digital file and imported that into Autocad where I scaled it up to full size and plotted them on my large format printer - you can do the same at a print shop as well if you do not have access to a CAD/Plotter
After I had my patterns it was just a matter of cutting them out and tracing them onto the foam.
also for a guideline I kept Clay Bumble and using my sharpie marked where each pattern went to use him as a guideline.
I started at the shoulder and worked down using the naming convention of
L1, L2 etc.... L meaning stage left 1 the pattern # and on the back side of those patterns I wrote R1 cause flipped they make the right side
only thing I ended up modifying was the legs cause they didn't allow for the thickness of the feet but it was an easy fix but overall it was a good way to create a large costume off a small model.
in the future I might even try doing this off a toy figure and see how that works -