Displacements that don't look like butt

A Gentleman's Mustache

L1: Registered
Jan 1, 2016
9
0
Specifically mountainous terrain. I use the sculpting tool, pushing to be specific, but when I try to emulate natural-looking terrain, it just ends up looking blocky and awkward. Not to mention that it is incredibly time consuming, only to end up with a product that looks like it belongs in an N64 game. Are there any guides to making cliffs/mountains that both look good and don't take forever to make?