I would advise you to read a lot of books in English. But not any kind, read good authors who actually know how to use a beautiful language. Ask book sellers they could tell you which one would fit your liking. An other I really like and one of the best (in my opinion) is Joseph Conrad. All the more that he learnt English (he was born Polish) but became so good at using it that it could only inspire anyone learning this language. :)

Sometimes people have me read what they have written and I explain to them where mistakes are and how to improve it during a class.

My answer is very simple: you just have to write, it´s like how does one learn to swimm? swimming...and so on.....so you just have to write about things you like and of course read a lot, to get ideas, new ideas and also come up with your own ideas. Hope it helps!!!

hello samin

Hi Samin, I suggest that you read italki Notebook entries, write some of your own and join the English Writing Group: http://www.italki.com/groups/3116