Started blocking out this stylized robot based on the concept shown by the very talented Jesse Carpenter:  https://www.artstation.com/jessecarpenter 

Here is the concept by Jesse: https://www.artstation.com/artwork/ZGO60 

Here's the beginning blockout sculpt in zbrush: 

Just getting some basic shapes in there to use as landmarks for refinement.  I generally really enjoy this stage.  I keep things as low poly as possible and I'm not afraid to get a little loose and dirty with it and clean it up later.  I feel like the more you do that, the more interesting the shapes become.