Proper Grounding PDM harness?

Hi guys,

Still researching on my own, but basically here is where I am:

I built the full chassis harness for power (12V) circuits only. Now I need to design the grounds. So from what I have researched the best method would be to run all the grounds to the engine, but that seems impractical. What I am thinking is single main ground from the battery to the engine, and then a large ground to the chassis from the engine? Ground all relative circuits (headlights, radiator fans etc to the chassis via short grounding wires.

Not claiming to be a genius on this obviously. All help appreciated.

I find it to be convenient to have a good chassis ground near the PDM that things controlled by the PDM are grounded to. So you basically have two wire power leads to each device.