A question my students often ask me is how do you know what to emphasize/de-emphasize. I showcase my "first impression" or what attracted to the subject. It could be a single person in a group, the sunlight on a mountain top or a texture on rusting metal. Something first grabbed my attention. Whatever it is, this should be your star. Think of the other elements in the painting as supporting members; they are necessary but must be played down. So always ask the question, "what is this painting about?". If you can answer it, you're on your way to compositional clarity. A vignette is often a good way to get to the point.
