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 FitchThe cake had a trick candle that wouldn't go out, so I didn't get my wish. Which was just that it would always be like this, that my life could be a party just for me.
Janet FitchMost people write the same sentence over and over again. The same number of words-say, 8-10, or 10-12. The same sentence structure. Try to become stretchy-if you generally write 8 words, throw a 20 word sentence in there, and a few three-word shorties. If you're generally a 20 word writer, make sure you throw in some threes, fivers and sevens, just to keep the reader from going crosseyed.
Janet FitchMy father was an engineer - he wasn't literary, not a writer or a journalist, but he was one of the world's great readers. Every two weeks, he'd take me to our local branch library and pull books off the shelf for me, stacking them up in my arms - 'Have you read this? And this? And this?"
Janet Fitch