Hey, this thread has been super interesting to read. I would like to respond to everyone but I don't have time for that, so I just want to share a thing you guys could use in your own campaign.
Blank hex map
(full-sized PNG so you can use it, too)
Here's how I used the hex map, maybe it will inspire you.
Cult of Xul's map
(JPEG because nobody is going to use this)
This map probably needs a brief explanation.
First, I printed out the blank hex map above and then made a topographical map and added some features from previous modules we had done or stuff I had just made up.
Watching Questing Beast's tutorials on this really helped me draw this. Each hex is 6 miles, so it will be really easy to connect into a bigger hex map. Forest and topographical features are pencil, road is pen, water is blue pen. I drew a bunch of weird little symbols on the map to represent different features.
Then, I wrote about 2 pages of history notes and came up with a (work in progress) key to the map. The numbers and features are left intentionally vague to the players, but I'll explain them to you briefly: (Note: * = a module)
1 is Hirot from Doom of Savage Kings*; 2-10 are randomly generated villages, into some of which I put details. Most notable of these is #2 - the town of Hole, an Anarcho-Syndicalist peasant town. Hole was the first place the characters went after the 'funnel.'
11-12 are ruins of towns that I am just going to freestyle/bullshit if they go there.
13 is just the Keep from on the The Keep Borderlands*. They haven't gone in that direction yet and I am not sure if the will. (read it a long time ago, never used)
14 and 15 = A and B. These are modules that the players have cleared. A is Tower of the Stargazer*, B is The Portal Under The Stars* from the DCC rule-book.
There are also a few other unmarked symbols (like a Cross and a lake looking thing) directly on the map that correlates to unmentioned modules which I have read. Hooks to these places are on the Rumor Table (possible subject of another post, but not now).
Just a bit of history on how this map ties into the 'campaign.' They got this specific map after about nine sessions running through various modules. First session was Portal Under the Stars, next one was Tower of the Stargazer, then three in Doom of Savage Kings and four in Fate's Fell Hand. Take note: Nothing from Fate's Fell Hand is on the map because it took place in a pocket dimension. At the conclusion of the 9th session and Fate's Fell Hand, they had been given a reward to instantly travel anywhere in the multiverse. They told me that they wanted to return to Hirot for the next session.
So I made this map and wrote about 2 pages of history/notes for my own usage. They got this map at the end of the 10th session, and then had it explained a bit to them at the beginning of the 11th while adding in Rumor Table rolls. The map was very useful and we referenced a lot. I suspect we will get an enormous amount of value out of this map. Hexes are so versatile. It would be very easy to tie into the Wilderlands, Hex Crawl Classics, Fight On or anything else with an expansive hex world.