A sub-editor collects reports from reporters and prepares articles for publication by correcting errors, checking facts, and editing for style and clarity. Some key qualities of a good sub-editor include having a strong news sense to identify important elements, understanding the publication to edit appropriately, maintaining objectivity, and ensuring accuracy by verifying all facts and details. Sub-editors must also be well-organized, fast-working, calm under pressure, curious, and possess strong language skills to effectively edit content for readers or audiences.