Dave analyses a PCB layout from the EEVblog forum and covers all sorts of tips for SMD layout, component placement, routing, layer stackup, controlled impedance traces, supply planes and power bypassing. Original forum thread: https://www.eevblog.com/forum/beginners/first-4-layer-pcb-traces-on-each-layer-a-good-idea/ Forum: https://www.eevblog.com/forum/blog/eevblog-1323-pcb-layout-review-analysis/