Map + clues

Here's my campaign map, or the SE quadrant of it.  New things are added as I prep them.

My campaign consists of three layers of adventure, superimposed.

At the bottom layer, there is a square crawl. Given the vast number of possible location, any content existing on this level is very likely to be missed. Because of this, the square crawl basically relies on tables for content. This means that I can have a dozen towers on the map and only have content for six of them, or hundreds of wilderness-squares and only content for twenty. So far, my players have engaged with the square crawl exactly once so this seemingly limited content is actually plenty. If I were to run out, I'd write more. Until then, it's just a waste of prep time - especially since d4 Caltrops got everyone's back.

At the second layer, there is a point crawl of locations connected by roads or trails. This is what my players mostly engage with so this is where I focus most of my prep. At the points of the crawl are adventure locations, set piece encounters, small scenarios or key NPCs. Here I also slot in adventures made by others when I find some that fit my aesthetics and tone well enough. So we've played Curse of the Shrine Goddess in this way, and I've placed a couple more.

The final layer consists of an investigation-mystery that provides the default point of engagement. This is basically a poor-man's CoC, with handouts containing clues for the central investigation into the relics of St Severend/Severinus as well as other mysteries more related to the history of the campaign setting (Why did Severend's holy mission fail? What happened to the Witch King? These kinds of things).

The third layer is the reason for my interest in different clue structures. Previously, I've outlined the elimination or guess-who structure where each clue cuts the remaining possibilities in half. This allows you to eliminate options until you eventually only have one left, which is the correct answer. The method have survived the first contact with playtesting: in Sourn, my players DID figure out the who the murderer was in about two hours without any pointers from me, DID NOT perceive the underlying structure, and were consequently super impressed with their detective skills and their luck. A great success (and a secret they must never know)!

So with the guess-who structure seemingly doing its job, it's time to introduce a second structure: the triangulation. The idea of triangulation is this: if you don't know where you are but can observe some landmarks whose position you are familiar with, you can use their bearings to determine your own position. So if your first clue is "east of X" and your second clue is "south of Y", you basically have the row-column coordinate of the thing you are looking for. You could also use it for social relations: "relative to Mr X" and "co-worker of Ms Y".

Here's a version, using distances instead of directions, which creates two circles with the target at their intersection. (Note that unless you're super skilled at measuring you'll probably end up with circles that intersect twice, so you'll need three distances or some constraining factor). Travel speed is 18 mi per day. 

The Saint's Hand 
No sooner had Severinus died, than many accounts began to come of miracles because those who touched his severed hand regained sight if sightless or speech if speechless, and those who had terrible coughs could again draw breath like young people. After five days at a stake in Mersault, the hand was taken down in secrecy and smuggled to a tomb seven days’ travel by road from there, and Ygdrain was powerless to find it. 

 “A swollen tongue” – Excerpt from traveler’s log 
At one time my tongue became uncomfortably swelled up, so that when I wished to speak it usually made me stutter, which was somewhat unseemly. I went to the tomb of the Saint’s Hand, eighteen miles from Croix-an-Tour as the bird flies, and drew my awkward tongue along the wooden lattice. The swelling went down at once and I became well. It was a serious swelling and filled the cavity where the palate is. Then three days later my lip began to have a painful beating in it. I went again to the tomb to get help and when I had touched my lip to the hanging curtain the pulsation stopped at once.