"Always ask permission."
You'd ask someone for permission before photographing them, wouldn't you? Okay, sometimes I'm guilty of being a tad rude shy, but ah, I'm not going to solve the eternal debate between genuine candid shots and ethical snaps of people who are only too aware of being immortalised to act natural.
Michael believes in asking permission from whatever it is he's about to photograph. Land, trees, piers, you name it. (He says he's not as keen on making photographs of people because apparently we can't sit still.)
One particular example he gave was when he paid a visit, the first of many, to the Nazi concentration camps after the Berlin wall had come down. The eery energy and horrific memories of the place intrigued him, but he didn't start snapping away immediately.
"I made a pact," Michael said. "None of this would be for profit. I'd give it all away." What's important to Michael was being 'allowed' to photograph and study one of mankind's darkest moments.
This lesson is probably my personal favourite, although I suspect it's because of the spookiness.