When I began, the layout room had a series of outlets on all 4 walls. The layout was a large island at the time, powered by surge power strip attached to one of the legs.
Since then I have tapped into the outlet circuit, and installed a switch with a pilot light near the door to the room. This now feeds a separate loop of wiremold conduit on the wall. The power packs are mostly at the far end of the room whre the island (now peninsula) extends to the wall, and are fed thru a plug in surge outlet set. I know just where to look before I leave to make sure the layout power is off, and the original outlets stay hot for tool use whan I work on the layout.
Phil