When I'm developing PCB, I decided to split the PCB into 4 main zones, absolutely symmetrical from both sides:
It was a little bit challenging to provide proper grounding w/o undesirable current paths. I did some minor mistakes with the grounding in REV 1.0 but I think I fixed it all in REV 1.1.
Also, the additional spacing between unisolated GND and isolated GND was added.
I used 0603 parts (minimum size) for hand mount ability. Unmounted parts - temperature sensor(U9).