Wiring is crucial in PCB design, impacting performance, electrical requirements, and aesthetics, following specific principles for optimal functionality and meeting requirements. Keep in mind priority of power and ground wires, position of high-demand lines, grounding for oscillators, wiring techniques, avoiding loops, and optimizing for production and maintenance testing. Pay attention to signal line and power line width, pad and via requirements, and pitch requirements for pads, lines, and vias.