scale

sorry if this has been asked before.i am making an outdoors scene with the camera looking out over a mountain range.how would i give that since of scale to were it just vast and huge?(the mountain range won’t be the main part of the scene,there with be a character in the forground that the camera is focused on)

If you mean something along the lines of this
http://comps.fotosearch.com/comp/PDS/PDS070/woman-looking-over_~AA012991.jpg
then just arrange your scene that way.
The sense of scale will be recognized by the viewer’s brain.
As long as you model everything to the proportion of a human.