My memory of wiring techniques is pretty rusty but mainly try not to run any low voltage control wiring along side something that produces an alternating field. I try to make sure that the bikes sensors that I tap into for data logging ( TPS, MAP, TACH, CRANK, ect...) don't get routed along side wiring from the fuel pump, 12 volt solenoids that get pulsed off and on, fuel injectors and the items that Dean mentioned. On my bike I have twisted the power leads to the fuel pump, fuel injectors, stick coils, air shifter and boost solenoids, water injection pump and air compressor to name a few. This is to keep them from inducing an AC signal in to their adjacent wiring. I would not use coax on a sender unless it was factory wired that way or I had determined it was definitely giving me an error. I've seen a lot of noise get amplified in a wiring system when a coax cable gets installed and the shielding is not properly grounded to a good grounding bus.