Worbla, you guys. (Posted 16th December 2013)
This stuff is ridiculously easy to use, I love it <3 Shame it's so expensive, though.
I've started re-making the templates for parts from some stiffer card (a lot of the paper ones from last time have torn), and begun work on cutting out bits and pieces. I only have one sheet of foam and Worbla right now, so I gotta be careful! Starting with the smallest pieces seems to be the way to go - don't wanna waste all that material so soon!