Adding depth to a map can make it stand out (pun unintended), but it can be difficult to generate 3d perspective from a flat plane within QGIS. In this example, depth outlines are created with marker symbolizers of vertical lines, offset vertically and overlaied with another copy of the layer. The urban areas layer is additionally offset to create the built-up effect. Labels are created with white text, a black buffer and drop shadow.
The print renderer introduces some unwanted artifacts in the border, but this is probably fixable with a bit of tweaking.