I've noticed that not a lot of teachers on italki concentrate on developing WRITING SKILLS. I'm not sure if this is because students are not generally interested in developing their writing skills, or because teachers find it challenging to organise writing courses online.
I've developed a course to help you improve your writing in which I teach you how to write better and give you written and audio-visual feedback. See an example here: http://www.screencast.com/t/c9olRwCmZf
So, if you're interested in writing better emails to your friends or preparing for an exam such as IELTS, TOEFL, PET, FCE or CAE , this is the course for you!