So, in the middle of my Captain |America WS build, I owe a friend a favour. He's asked for an Olaf costume, so I'm building it out of foam, and will finish it with polar fleece. Here it is so far!
Okay, working on the arms now. I've made a brace that goes inside the smaller "snowball", and it holds the arm, which in turn, is set up like Muppet arms. When all is said and done, the wearer will have his hands or arms dressed in white, sticking out through slits in the front, operating them like a rod puppet.
Put him in summer and he'll be a....happy snowman. Very cool build! Is your friend small enough to scale down to Movie height (compared to the princess, Christoph, etc?). Just curious what height you're goin for here? Regardless of that it's awesome...and now I'm going to go lookup polar fleece..