Map reading was very important; we had to get to know compass and map work, and charts etc, then we had to navigate with a compass , no map, and finally with no map or compass. In some parts of Sarawak in the '60's the maps had large areas marked "Unknown Territory", and we used air photos and the direction of streams to navigate. Of course the territory was in fact well known to the local tribes! (Ibans, Punans, Kenyah etc)
However Brumas' little clues sometimes help, but loads of elimination and guess work is involved , as you well know!
My luck has been good but I feel it is running out!!