My flippant response is "With a pen. On paper."
But since this month's RPG Blog Carnival was about RPG Cartography, I went the one step further and actually documented my process.
The full thing is here, but here's the scans:
First I need an entrance to the dungeon, so that's where I start. A small tower with some ruins.
And by the second scan I'm already adding my cross-hatching to the map. I enjoy this because it slows down the process allowing me to ruminate about how the dungeon will grow from this point in the back of my noggin' while I draw little lines and rocks.
And the next step is me finishing the rough layout now that I know what I want from it. If I haven't mentioned it yet, I don't really know what I'll be mapping until the map is already partly done in most cases.
Then it is time to thicken the lines and add some more details and work on the cross-hatching and fills.
And then I scan it "for real", crank the brightness and contrast, and post it to my blog
