Self-Editing for Fiction Writers by Renni Browne and Dave King: this is a well-respected reference book which teaches self-editing techniques, accompanied by examples and exercises. Topics include writing effective dialogue, avoiding too much exposition, mastering point of view, interior monologue and how to make your writing more sophisticated. It’s become the go-to book for many courses, too. It’s quite dry and serious in tone, though, which isn’t for everyone.