This works with ALL areas, but only some spots are documented. So if you find a common pattern somewhere be sure to let us know in the forums and we'll add it here.
Heres some quick guides to get some of the common quests and runs without needing to resort to using maphack.
Once you nab the waypoint there are only three possible paths that you can take to get to the next level. Here they are:
The action that actually triggers the portal to leave is nabbing the waypoint. However, I still say nab the waypoint. Why? Because without the waypoint, you will have far too long of a trip for these runs to be efficient...
To speed up finding Nihlathak in the final area, he will be in room opposite the room with the champions in the back. With this being said maximum rooms u will check are 3 and not four now.
There are 4 patterns
If you come out of the door and you can only move:
UP RIGHT, next level is UP LEFT
UP LEFT, next level is DOWN LEFT
DOWN RIGHT, next level is UP RIGHT
DOWN LEFT, next level is DOWN RIGHT
I don't mean upper left or downleft etc etc of map...Its the road leading to the top left/right etc.
Another way to think of it is, in the hall or room you start out in, pretend you are in there yourself and looking towards the only direction that you can get out. now, simply follow the wall that is to the left of you
So always go to the left of which ever way the room or hall points to. More often then not it will be really close or diagonally across the map. This holds true with a lot of the "underground" maps. Not always the case though. Heres some examples, the red arrow being the direction that the room points, green arrow being the left of the red arrow