This involves more than I can discuss here, but do it. Read the writers of great prose dialogue-people like Robert Stone and Joan Didion. Compression, saying as little as possible, making everything carry much more than is actually said. Conflict. Dialogue as part of an ongoing world, not just voices in a dark room. Never say the obvious. Skip the meet and greet.
Janet FitchI wandered through the stacks, running my hands along the spines of the books on the shelves, they reminded me of cultured or opinionated guests at a wonderful party, whispering to each other.
Janet FitchWhenever she turned her steep focus to me, I felt the warmth that flowers must feel when they bloom through the snow, under the first concentrated rays of the sun.
Janet FitchAs an artist, you can never get what you want. What you do never approaches what you want it to be.
Janet FitchAlways tell us where we are. And don't just tell us where something is, make it pay off. Use description of landscape to help you establish the emotional tone of the scene. Keep notes of how other authors establish mood and foreshadow events by describing the world around the character. Look at the openings of Fitzgerald stories, and Graham Greene, they're great at this.
Janet Fitch