A switching power supply layout is a balancing act between thermal, electrical and EMI considerations.
Good switcher layouts tend to look deceptively simple, hiding a number of very important traits.
High frequency switching nodes and gate drive traces are kept short; high current routes are large, or rendered as pours. It's not always obvious at first which nets are high frequency or high current, so consulting the datasheets is a must. Correct layout reduces noise considerably. Demanding high power designs contain thermal vias, maybe dozens or even hundreds, to improve inter-layer current flow and thermal conductivity.
