Describe all externals in your story—settings, objects, other people, etc.—through the eyes of a character instead of through the "neutral" eyes of the narrator.
This technique accomplishes three things:
1) It keeps the narrator out of the picture. (The writer’s goal is to stay invisible.)
2) It’s a time-saver: Readers get necessary descriptions of the character’s surroundings while learning about the character. This moves the story along faster.
3) It’s a handy way to weave in back-story unobtrusively, without resorting to longer flashbacks that can break up the “now-ness” of the story.