See it before you shoot it. The image is made in the mind before it is captured on the frame or CCD. A very basic lesson that I find few of my students remember these days, what with super fast digital cameras and the infinite ability to just 'fix it later'.

So here is an old man, perhaps you know him, talking about this issue. Full disclosure; I have never been a fan of Adam's work, finding it rather overly technical and cold. But I respect his rigor, and his commitment to the craft, and the singular passion and belief with which he carried it out.