Okay, I felt myself getting bogged down with trying to make the walls perfect, so I stopped that. I went back to a more abstract, game-boardy look for now so I can just get enough done to play around with them (I know myself).
So, here is Tile 3:
For the rest of the triggers, take the number of the face you exit a tile, and the number of the face you're entering and mash them together. If that number is odd, the odd triggers fire, if it is something like 55, double triggers fire and double odd triggers.
Specials are rarer events, they might affect a whole tile like a cave in, or indicate that it's web-filled or something. I will need to make a chart. Actually, I eventually want specials to be unique tiles, like chapels, or large ponds or something. But I mess with that only after I have enough standard tiles done.
Triggers only fire once, when you first enter a tile. All triggers fire at once, so if you got two encounters . . . well, maybe they'll fight each other. I know knowing where the treasure and monsters everywhere on the tile are is not realistic, but it seems the most streamlined way to do this so someone won't game the system. I'm guessing you could easily graft on more complicated systems if you wanted.