My test sketch, laying out room space just to get a feel for fitting objects proportionally to a space.

My first cleaned up concept of the space from top down identifying objects and arrangements.

The initial grid template that I use to translate my top down map into the 3D space

The broad 3D objects I put in before any detail to get a feel for the size of everything in case on necessary adjustments

Initial cleanup, taking some of the rough details and defining them further, including smaller objects or things placed on top/within