Generally when we are creating renderings what we are trying to create is the concept of the design. And lets face it, most of our clients when presented with a design will make comments about the colour schemes or the type of furniture. I have found that a good way of dealing with this is to model the building almost entirely in a white color. This way they look at the building as a whole form and don’t focus on the wrong things at the design stage.
If I need to model contextual information I model the elements in a semi transparent white colour.
The image above was a very quick render which clearly shows the context of the building to the site and additional things like vehicles and planting being shown indicative by nature of the transparency. This also works well with furniture internally to show possible furniture layouts