Sadly there is no tutorial for these. This piece is my own design and so are many of my other projects (unless stated other wise). But how I actually do make projects like this is by just analysing the object or character. (sometimes this takes months) Because of how different 3D Origami is from traditional origami you have to think of it as a medium like drawing or painting. That helps me but then again I have been doing 3DO for roughly 4 years.