Vocabulary. Words are the tools of the writer and you must choose and use them well. And although it can sometimes be tempting to use more grandiose words, simple words which everyone can understand can be far more effective. In speech sometimes just using 'said' is better than interrupting the flow with an alternative, such as exaggerated or expostulated. And be economical with adjectives. The vocabulary you use must be clear rather than complicate.
W is for writing and to write articles, stories or books, you do need to write. Too often it can be easy to delay the writing process by carrying out even more research or doing other things but there has to be a time when this stops and you actually get to write, particularly if you are to realise your potential.
EXtra. Do not forget the extra touches. Your article may be done but have you considered adding a resource box, writing a short piece about yourself, any illustrations you could include or ways which you could make your submission more appealing? In a book sometimes just the inclusion of an opening quotation or preface can add something extra to your work. As in so much, by doing that little bit more, the extras could reward you well.