...and the smallest wires in the circuit match the breaker.
You can also use sub-panels, which can really simplify the wiring
. E.g. all the gadgets at the nav station could go to a fuse block inside the nav station that is in turn fed from a single
breaker in the panel. That way one breaker/switch brings the whole station to life. (As long as said gadgets have their own switches so that you can turn one off if not needed.) All of my LED cabin lighting
goes to a switched terminal strip in each zone, and those switches all lead to a common bus that is fed from a breaker. My cockpit
instruments (sea talk bus) actually require
a sub-panel because the autopilot
has different fusing requirements from the instruments. So one might as well hang a power point and some lazarette lighting
on it too, without extra cables
running back to the panel.