Writing in itself is quite a difficult task but when you are writing in a language that is foreign to you, this makes the task much harder. I’ve been working with ESL students for nearly three years now and I am going to pass on the best tip I’ve learned to help you improve your English writing.
Write your work in your native language first.
Writing an essay or business report is a challenge at the best of times and when you are writing that work in a foreign language you have to first decide what you want to write and then translate it all in your mind before you even start writing. There are two different processes going on here, a) you are thinking about your work, what you want to say, and how you are going to say it, and b) you are also working on translation. When you try to do these two processes at once, both your work and the standard of your English will suffer. The best thing to do is write your work in your native language first so you can get all your ideas down on paper (or on screen) and say exactly what you want to say. When you are happy with this, then, and only then, should you work on translation.
When this is finished pop over to my article on how to proofread your own work so you can really polish your work and make it shine.
If, however, you are still struggling there are many proofreaders out there (including me) who can help you out or you can try a translation service.