Here is where to start. And this is very, very, very important.
All good pictures (as opposed to listless, bad pictures) are written in sentences of shapes. These shapes can be as sharp and clear as a bell or implied, evoked and elided like smoke. Or they can be a combination of both. Lines are just long thin shapes related to the big shapes either side of them (which they both describe and are given context by).
The moment you stop writing your picture in this way, the moment you just make unrelated marks, the thing gets dirty and confused, and the eye snags and drags over the image, becoming bored and 'losing the thread'.
Go and look at a picture you really like. See how your eye can glide around in a continuous melody of shapes each related to the others, 'hooked' to each other, mashing, kissing, pushing, stroking, locking, knocking, shoving, pinching, caressing each other. This is as true for Rembrandt or Velasquez, Waterhouse or Sargent as it is for John Jude Palencar or Picasso, Monet or Modrian or Morandi or Muncha. Even the orange picture with the severed head advertising the 'Portfolio' on this page or the strap-line image at the top are expressive because they are written with this understanding firmly inside the artists who made them.
It is the difference between artists who write expressive, fascinating work and those who write dead statements about what we already know.
Read more: http://www.conceptart.org/forums/showthread.php/294954-Abstract-approach-to-painting#ixzz3LInxDiGp
Recommended book from that thread: A Proven Strategy for Creating Great Art by Dan McCaw
From top Amazon review: