Foreground

Shots are more dynamic when they include objects at different distances. So including objects in the foreground helps give a shot depth and three-dimensionality.

Without any foreground, the shot on the left is fine, but, the shot on the right has foreground elements (the rocks) which makes the image more dynamic and three-dimensional.

Not every shot can have foreground elements, but when reasonable, consider this option.

 

No Foreground

With Foreground  (Rocks)