What's some good ways to practice robotic torsos?

I'm used to more bendy bodies and so I find it difficult to draw a rigid armored body.

This can range from stiffer, bulky, military grade robots comparable to Zaku Gundams to fluid, slimmer and overall dynamic robots like Cyber Dragons from Yugioh or some Mavericks from Megaman X. While I sometimes do squishy robots like most Megaman characters: that's missing the point of having a robot that's heavily mechanical.