The article should not use rarely used words, unless it hits straight at what is being conveyed. The idea being conveyed is more important than the words. Correctness of spelling is mandatory. Language It is better to use short sentences. Use ample punctuation to make sure that the reader splits long sentences as you want him to.
Grammatical correctness is, of course, mandatory.
Style Similies and metaphors make the reading interesting. They should not be too heavily used, because they can be distracting. Usage of examples and anecdotes also fall into the same judgement. Citation Citations tend to increase the credibility of the ideas. It is important that they are apt and are used in the sense that the original author used those words.