It is a mistake for a sculptor or a painter to speak or write very often about his job. It releases tension needed for his work. When one dots all the i's he ends by being boring. Even when painting from nature, one must compose. There are people who fancy that this is forbidden.
Painting is only a bridge linking the painters mind with that of the viewer.
You must not paint everything you see, you must wait, and wait patiently until the exceptional, the wonderful effect or aspect comes. Then if you have sense enough to see it, well, that is all there is to that. If the man who paints only the tree, or flower, or other surface he sees before him were an artist, the king of artists would be the photographer. It is for the artist to do something beyond this. I have never tried to do anything but get the true relationship of values.