This is my own way of creating pixel art out of blender. This started as an experiment to see if Blender could produce pixel art without any outside applications. The result is pretty accurate in my opion and not super difficult to setup.

This blend is specifically setup for an original gameboy palette, but this could be changed in the node editor.

Important things to note:

• Low resolution size - If you want double or quadruple sized pixels just import your finished images back in to sequencer and up the scale. If you want higher resolution graphics like SNES simply up the size by squares of 2 (64, 128, 256, 512, 1024)
• Antialiasing is off - everything blurs if you turn this feature on.
• I'm using FreeStyle - Two line sets, one for a black outline and another for a transparent black line for interior contours. This helps make contours more visible when shading doesn't do the job.
• Materials - Don't really matter much. Toon seems to do a good job, but most materials look good to me.
• Compositor - This is where the palette and real retro feel comes from. I'm using one color ramp for the scene compositing. Any amount of colors can be used, but its important that blending be set to constant to preserve hard breaks in color.