There isn’t a universal recessed lighting layout that fits all kitchens. The cabinet layout, ceiling height, the type of recessed lighting fixture and the light source make a difference in locating the recessed lighting. Best to consult a lighting professional or a lighting distributer salesperson with your kitchen's unique details.
The “rule of thumb” is to place the downlights at the counter front edge line, so that its light cone or scallop pattern has some relationship to the cabinet or room plan, yet still provides the kind of lighting needed, either task or ambient.
"Light scallops" depend on fixture cut-off and the location of the fixture away from the wall or cabinet face. Sometimes the light scallops from recessed downlights work well in the space, and sometimes they can draw attention to the light itself and away from the cabinet details.
Lighting Tip: If there is ample undercabinet lighting for cooking tasks, room downlighting needs just to give light the upper cabinets and to provide safe movement within the kitchen space.
Downlights used exclusively for general room lighting where there are other layers of light, do not have to be placed at the counter edge line: in some large sized kitchen spaces recessed downlights can be centered in a wide aisle walk space and lamped with a simple household lamp or compact fluorescent lamp.
