[Stiglr]

It's not necessarily so hard to work with the "subshapes" as you call them.

Just start with the basics, isolate them with rectangular areas, perhaps indent a tiny bit and extrude the "inside" of the area in. You can make the shape a bit more detailed by inserting vertices and moving them to create the shapes.

As I said, this is best demonstrated rather than written in a post. PM me if you'd like to share a screen for a demo.