Characters who are either too good or too evil are too flat! Settings–whether rooms, cars, or countrysides–that are unmitigated beauty are likely to be unbelievable. Pick and choose the good and the bad. This exercise is intended to raise your awareness of both sides.
First choose an animal or an insect that you find repulsive. Write everything about it that is awful, in vivid detail.
Now find three positive things that you can say about that entity. Describe these in equally vivid detail.
Try this with people as well–if you’re sure your words will remain private!