Balance depends upon the location, size, color, shape and direction or orientation of map elements.
Less weight peripherally located upper half right side isolated elements large elements red elements regular shapes compact shapes vertically oriented centrally located lower half left side elements in groups small elements blue elements irregular shapes diffuse shapes horizontally oriented White space is needed, but you don't want too much. A general rule is to place the largest scale map that will fit in the map area while space remains for the title, scale and legend, north arrow, etc. These ancillary items must be present, but should not be too large or too small. Dark and light shades and hues, variation of line weight and point size of lettering. There should be an immediately visible hierarchy of these elements.