No unnatural or asymmetrical body parts.
No incorrect or inconsistent proportions.
No generic or overused poses.
No unfinished or rough areas.
No flat or unrealistic color palette.
No poor lighting or shading.
No distracting or out-of-place background elements.
No inaccurate or anachronistic details.
No visible grid or construction lines.
No low-quality or unprofessional execution.