Good Composition: This photo has good balance and symmetry.
The color from the car matches the color on the road which is also an
example of static gradation.   

This is also an example of good composition.
It shows dominance because the leaf is the main
topic of the photo. It also shows symmetry. You can see
contrast in the color. The leaf standing out as conflicting colors
from the concrete behind it.  

This is an example of bad composition. There is no "topic" of
this picture. It shows no balance between the objects that are shown.

This is an example of decent composition. The address is shows dominance,
but the number is off center and has too much empty room at the top. This is a
bad example because the symmetry is off.