Design and Compostion of your painting can either help it or hurt it. There are several methods for creating good composition in your paintings: The rule of thirds, the golden mean, the simple cross. There is symmetrical and asymmetrical compositions. As an artist you will be making these decisions as you plan out your piece. I tend to use the simple cross method. you divide your canvas into four equal parts, you keep any major object in your design off of the four lines and out of the direct middle, you work your light to keep the eye moving and you are good!
Thanks for posting this Al, very informative! I use the rule of thirds when designing my painting. That could be light and shadow, like 2/3 shadow in the composition and 1/3 light or visa versa. The landscape too, place the horizon in thirds also. For a big sky feature, 1/3 land and 2/3 sky. Never place your horizon line in the middle.