Steps 2

I used sketchup as a base, which in this example was kinda not needed as it was only used for the vanishing points.

There is a missing step after the first one, because I did sketch in the placements of the object in lines before I did the clean perspective drawing you see at the current step two here, kinda makes sence to just sketch and change stuff before you spend more time working the perspective out.

At step three you see I like to use the soft round brush to block in the lights and than later go and refine edges.

At step six (sorry didnt put number on them) I added texture on the floor made by a multiply layer choosing a light value color, and the window reflection I painted in softly than I kinda ereased to make textures on it, can also use mask for that.

Maybe not that mutch more to say, during the last stages I used a color balance to pull all the colors towards the red (kinda like glazing)