SketchUp has been used mostly by Architects as a way to convey designs and ideas. Recently, with the integration of importing/exporting capabilities of SketchUp and Google Earth, SketchUp is being used as a way to model building quickly with phototexturing techniques.
The workflow is quite different then typical architectural examples. Usually I will import the CAD geometry as a reference and develop a detailed model of the facades, windows, doorways, roof pitches, etc. However for Geomodeling, it is more about creating a massing model with less detail and allow the phototextures to convey realism in the model.
To my disappointment, most of the work for geomodeling is done in Photoshop creating the textures. My personal workflow tends to lag depending on the quality of photos taken. Below is a video time lapse of the process.
It is best to limit the amount of Photoshop work that is needed by creating generic textures for repeatable facades. The challenge is making these NOT look like a tiled texture. Other techniques used in SketchUp is the Matched New Photo (Photomatch). This feature allowed me to estimate building heights that are proportional to the building footprint.
Lastly, this model took a little over an hour to complete; which is really fast when considering the amount of detail and size of model. Enjoy!