As I mentioned in the introduction thread, I'm a long-time lurker but have not tried posting until now.
I draw most of my maps by hand: I use non-repro blue to sketch in the lines, followed by pencil (first with hard 6H and then soft HB lead), and finally I ink them in with Koh-I-Noor Rapidograph technical pens. though I do use AutoCAD for the more complex structures, I prefer to draw my fantasy plans manually since CAD tends to look too "sterile". Due to the fact that the majority of my drawings are for sale or publication, I can't post any of my completed works in their entirety, but what I am able to post will give a good impression of what I am able to do. Through my lurking I have found a lot of inspiration from looking at the various maps posted here, and I hope I can return the favor. I'm always open to suggestions and intelligent critique as I'm always working to improve.
You will notice that none of my maps fit neatly to a grid. I know that since the 3rd edition of D&D the D20 rules have been designed to accommodate miniatures, but as old-school gamers my friends and I rarely use them other than to represent our relative positions. Lately I've lost interest in the D20 system and have been leaning toward the Basic RP system from Chaosium, which does not require a grid or miniatures, so I've been creating my latest maps with that in mind.
I've tried creating grid-based maps, but find that they lack too much interest and realism for my taste. That's not to say that the grid-based maps presented here on CG aren't good; I'm often impressed by the creativity shown by people "sticking to the squares".
The first map is a cavern complex that I decided to draw on graph paper. This was for a game I Gm'ed quite a while back.
The second map is the forecastle of a Dwarven citadel drawn in AutoCAD, the citadel itself spans an entire mountain range and will have several other structures such as this.
The last map is a subterranean city built in a dry cavern within an extinct island-volcano. The city in intended to be a safe hidden port for smugglers and pirates.