Ten ways to acquire a sense of good composition:
1) Use the Greek Golden Rectangle.
2) Contemplate Nature's works whenever you can.
3) Master Gestalt perception.
4) Study sacred geometry.
5) Employ the envelope drawing technique.
6) View your initial outline in a mirror.
7) Turn your canvas upside down and gaze at it.
8) Be conscious of measurements, ratios, correlations, proportions, and relationships.
9) Be comfortable with both symmetry and asymmetry.
10) Divide your canvas into quadrants before applying construction lines. This locates the centers of your canvas both ways.
The following prevent you from developing a sense of good composition:
1) Being a slave to the grid method.
2) Being a slave to the pantograph.
3) Thinking in terms of "landscape" and "portrait" orientations only.
4) Believing that composition in photography and composition in painting are identical.
5) Convincing yourself that shading and/or the addition of other figures or elements will improve your work.
6) Being unwilling to revise and rework your painting at ANY stage of its creation.
7) Locating your vanishing points INSIDE your canvas rather than way outside it.