Firstly the character is designed:
Front side and head profiles are created, with these a 3D mesh is extruded to create the shapes.
Using the 4 windows of Maya, I extrude a square primitive from the torso outwards, adjusting the vertex loops to fit the shape of the 2D profiles, while ensuring the minimum amount of triangles. Quads are preferred when creating models.
Using Mudbox, I create a higher polygon model from the low poly base model, this high poly model will be extracted as a normal map to be applied as a difference on the Low poly model, giving the illusion that a low poly model is displaying the same amount of detail as the high poly model.