MicroStation v8i SS3 Beta 4 (8.11.09.119). 

- relatively simple 3D DGN, with a number of "recycled" elements from other designs (kitchen, doors, shelves)
- all lights are cells with "Place light" "built-in" (I usually use either Point or Spot - don't use IES profiles, at least for the moment, as it led to problems)
- all cells have mostly pre-defined materials, except where a specific material is chosen in the design process (eg.: chairs in the foreground - all except the green upholstery is predefined; TV - all except the image on the screen is predefined)
- I added the RPC person to get an idea of "scale" (great that these few RPC cells are now in MicroStation)

"Pre-defined" lights and furniture are obviously for being able to quickly get a design done. This method though is appropriate if you usually select from a previously defined range of products.
Some of the cells used were modeled more than 10 years ago... (eg.: Vitra "Visavis" chair - if I remember correctly, we modeled that chair ourselves, as Vitra didn't have 3D models then...)