The glow of streetlights and the like can add a nice bit of warmth, elegance, and atmosphere to a nighttime cityscape photo, but, of course, you do not get control over those lights, and they will not always be turned on when you are out shooting. It is not too difficult to turn them "on," and you do not even need Photoshop to do it. This helpful video tutorial will show you how to do it quickly and convincingly using Lightroom.