Let's start modeling!
For this piece, I decided to model in a type of zombie pose with the arms facing the front, because in the end it would be easier to match the pose from the concept.
I started creating ZSpheres with the overall volume of the character, focusing on basic proportions. After this part was done, I converted it to a mesh and started blocking the shapes, silhouettes and finding the apexes. Try to keep symmetry on as long as possible at this stage. After nailing the basic silhouette, I started to add secondary forms, building up muscle definition and transitions of sharp to soft forms.
Modeling various parts of the scene
Creating topology and UVs
While still in ZBrush, I decimated the model and brought it into Maya
to start creating topology for better posing and animation. I used the quadraw tool (from the new modeling toolkit in Maya 2014), to define the flow of the loops. After the topology was done, it was time to start the UVs. I normally use Maya to create the UVs, but you can also use ZBrush for faster but less accurate results.
With the topology and UVs done, I went back to ZBrush to start posing the character in the chair with Transpose Master. This stage is very important from a storytelling point of view ? the pose plays a big role in telling who our character is. Pay attention to contraction and compression, try to push the pose even further than the concept, and spin your model while posing to see if it reads well from all angles. Try to study photos of people in that pose or ask a friend to pose for you and take a photo. All this will help, as the more subtleties you add the stronger the character will be.
The topology and UV breakdown