You should have a strong center of interest, or focal point.  This is the element to which all other elements will direct the viewer.  You may have secondary elements, but attempt to have just one center of interest.  Use the other features in your painting, sky, trees, flowers, to lead and keep the viewer coming back to the focal point.  Doing this will also create a sense of depth and space  in your painting.

Technically, there are two kinds of balance in a composition.  Symmetrical balance (also referred to as  "formal"), and asymmetrical balance (also called "informal balance").  Symmetrical balance produces paintings that are restful, calming, and visually stable.  Asymmetrical balance is characterized by arranging related or unrelated objects of differing visual weights counterbalancing one another.  This can heighten interest, bring informalality, or even produce tension in a painting.  While both ways are correct, yet each offers different advantages and purposes.