I’m always fascinated to see old mapping techniques replicated in modern mapping software. For an example, see Robin Hawkes’s tutorial on creating hachure maps in QGIS. Which Patrick McGranahan followed to create this map of San Marino.
Maarten Lambrechts discusses how to make a dot density population map, in technical detail. He uses QGIS to process data for his home country of Belgium. The map above is one result (he also zoomed in on Brussels).