I've just managed to catch up with the Natural Navigator's latest media spot which was on the BBC's Country File program.
Here he gave Jules Hudson a few lessons in the lore of the NN, one example of which can be seen in the picture below.
This tree is a classic example of the northern hemisphere asymmetry, with more branches on the south side than north, and typically angled lower.
Using clues such as this Jules was given the task of navigating from A to B using the clues around him, and managed to make it too - though as can be seen on the figure below there were a few detours on his route (yellow) from the NN ideal (blue).
All good fun but if you want to see the show and have access to iPlayer hurry up as it will be gone within a day!