Seems to cover it. I think he said spot meter the palm and open up one stop. I think he said overcast will have to be solid white (blown out?) because there will be no shadow detail though, and only on sunny days can you get a texture.
When you use the palm trick, bear in mind that 1) you need to expose it in the same light as your subject or as near as possible and 2) the skin on your palm is rendered well on Zone VI so anything else in the subject area that has the same reading will look like the palm of your hand in a generally proper exposure. Not accounting for personal tastes. Adjust as necessary.