Best place to start? At the bottom.
Not a huge amount done yet, just the shell of one foot. I've marked out the other one from this so I can build it the same. Want to have it moving forward, although a lot of stompas out there, and the new GW concept art, seem to have these things moving quite quickly. I always imagined them as huge lumbering things that sort of waddle. So he'll be waddling forwards.
It's nice to have complete free reign over the design, something you can't really do with IG stuff. Bless those orks and their creativity!