Talking of ATA pilots etc I once read Alex Henshaw's book about his life as a test pilot. He was known for having an uncanny ability to find his way back to Castle Bromwich, where he used to test fly Spitfires from, in the foulest weather. He used a method that is stupidly simple that I use myself.
Any nearby power station will create a 'bulge' in the overcast if you are flying above it. It's blindingly obvious when you see it. As I have two power stations near where I fly from I use the method to great effect to impress people with my incredible navigation skills. Without telling them about Alex Henshaw of course...
