The third "boo boo" labeled "amorphous design" talks about the cornerstone of good composition. I have always thought of it as the diva (focal point) and her entourage, which consists of two smaller points of interest. These points should form a triangle (during the Renaissance many artists preferred the equilateral triangle, although most artists now use an unequal.) The points direct the viewers eye, practically providing a map of driving instructions. Many paintings fail either because this diva is not evident or her supporting cast does not exist, thus leaving the viewer floundering and uninterested.
The painting above was one I completed this winter. It fell flat until I heightened the distant land mass and sky- making the diva more apparent. The blue in the top left sky and the orange in the mass of trees left were my pivot points.
PS When you check Robert Genn's post be certain to sign up for his twice weekly letters. The post is one of his wonderful letters.