Chekhov used to correspond with aspiring writers, and once he gave this advice to Maxim Gorky when he was encouraging him to pare his wordy sentences: "When someone expends the least amount of motion on a given action, that's grace." The short story, by definition, embodies this notion of grace, because it requires such forceful compression to achieve its effects.
When I read students’ attempts at creative writing it is obvious immediately that most of them have not read much or widely. The aspiring writer must read everything he or she can to appreciate the myriad ways words are used and to what effect.
I would also suggest that any aspiring writer begin with short stories. These days, I meet far too many young writers who try to start off with a novel right off, or a trilogy, or even a nine-book series. That's like starting in at rock climbing by tackling Mt. Everest. Short stories help you learn your craft.
About a year after (my stories began being published), magazine editor George Scithers, suggested to me that since I was so new at being published, I must be very close to what I had to learn to move from fooling around with writing to actually producing professional stories. There are a lot of aspiring writers out there who would like to know just that. Write that book.SFWW-I is that book. It's the book I was looking for when I first started writing fiction.