Recently, I've been studying the work of David A. Leffel, the New York painter. I'll devote an entry to him later. He does wonderful work and has a great capacity for communicating his ideas to students. One of the finer points he tries to get across is the idea of having a concept for your painting. This could be whatever you're trying to get across to your viewer - the way light falls on a subject or an exploration of the treatment of edges, etc. In other words, not sticking to the reality of whatever it is that you're trying to depict. It's the process that distinguishes the artist from the student. There are decisions the artist has to make of what to include and what details to leave out or change. The painting itself becomes the reality and the subjects on the stand merely a point of reference.