Keep wiring for noisy stuff away from wiring for sensitive stuff to the extent practical. Do not create power or ground noise in sensitive circuits. Charlie also emphasized the importance of planning and designing the electrical system before jumping in and getting started with the actual wiring. Make a map showing the approximate location of each device or group of devices in the airplane. Sketch lines showing the interconnects.
Group lines together where it makes sense.
Refine the interconnecting lines to make sure that the interference rules are being followed. Sketch in the desired disconnect points. Done properly, this step allows most of the wiring work to be accomplished on the bench instead of while standing on your head in a small airplane. It also makes future service easier, enabling devices to be unplugged for maintenance instead of removing individual wired connections. Make a list of the connectors and the required pins on each one.