Keep it simple. Remember that the average reader should be able to comprehend the erudition. Although you should use a broad vocabulary of regular, non-technical terms, do not provide such a quantity of locutions as to impel those who aspire to derive serviceable information from the article to consult a dictionary or thesaurus. Stay on topic as many articles are criticized for length; sticking to the subject matter helps eliminate this. See: Wikipedia:Writing better articles and Wikipedia:The perfect article for more information..