This article by R Berdan is aimed at photographers but since its main focus is on Composition and the Elements of Visual Design. Since these topics apply to all areas of the visual arts I am sure readers will find it useful.
Berdan clearly discuses line, shape and form then develops the article with topic areas such as colour and composition. If you have encountered these topics before it is worth setting aside some time to read and refresh yourself on the basics. If you have never had any art training this article is a great introduction. As I say he is speaking about photography but these design ‘rules’ apply to all image making.