Make sure your other elements enhance the painting instead of detracting from it. One object, figure or color should be your focal point and everything else should flow from it. Remember, a whale can take up a lot of room. For a sci-fi author, following the dirty rainbow means finding the right track through the story until the conflict is resolved and the pot of gold retrieved. For the artist, following the dirty rainbow talks about object placement and how it is perceived by the viewer.
Many new artists like to plunk all there objects in one place on the canvas.
There is too little white space and too much stuff. Additionally, there is nothing to draw the eye from the 'front' to the 'back' of the picture. When you begin to design your electronic painting, make sure you place your elements in such a way that the picture is not static. Bunching your objects together creates a dead zone and limits the movement of the piece. Even still life paintings require objects to be situated in an interesting manner so as to allow the eye to arc over the page.