You also need to think about what kind of thin you are writing. The language in a story, for exemple ,should be EXPRESSIVE , but the language in a report or an article should be much more INFORMATIVE . When you are writing a formal essay giving your opinion,make sure the INTRODUCTION gives a general idea of the subject. Later, in the CONCLUSION you should submarine your opinion. Each the time you write, you have to make a CHOICE about what you are going to do. If you do that right , then there's nothing to stop you becoming a good writer!