The obvious answer is that he or she produces clear, concise, and creative content using the best-chosen, grammatically correct language. (No small task!) Of course, the much bigger question centers on how this is done.
Here are seven traits of great writers.
1. You are an avid reader.
Great writers are voracious readers. Like musicians who listen to music to analyze it, writers analyze what they read. They pay attention to structure, technique, and word choice, and incorporate these techniques into their own writing.
2. You collect words.
Great writers collect words with the intent of using them later. I keep a running list of my favorite words in the notes feature on my cell phone. Here are a few of them.
3. You pay attention to language, no matter where it is: commercials, conversation among a group of girls at a shopping mall, Twitter posts, etc.