Adding a cityscape in the background of an illustration really ups the 'wow factor', but can be an unacceptable amount of extra labor. A little 3D can change all of that. This video series uses Google Sketchup as a tool to speed up the process of creating a detailed background. Eventually you'll paint over the 3D render, but it serves as a fantastic 'under-drawing'. Note: This three part series won't show you every button to press in sketchup, but instead - a compelling reason to figure them out.