Most people spend lots of time every day using social networks such as Facebook, MSN and Twitter or Renren, QQ and Weibo, their PRC equivalents. Social networks is an excellent way of accessing relaxed, natural Chinese in written form. It might not be obvious how or why, but communicating with native speakers in a relaxed way over the internet can be incredibly useful. Why?
You can practice in small chunks, writing perhaps a sentence now and then. This means that you don't have to amass the courage needed to write a blog post or an article, which is difficult for most people. It gives you the opportunity to take baby steps and still come a long way. Posts on Twitter are limited to 140 characters!
You can see spoken Chinese in a written form. Most people use a fairly colloquial language when they chat online. This is a veritable gold mine of useful phrases! On Facebook, read what the Chinese are talking about among themselves, and try to pick up some useful words and phrases. Even if you're an advanced student, you will still find much you didn't know.
You can use Chinese in a relaxed environment with more time available. If you're using Chinese with someone you don't feel very confident with, or if you haven't studied for a long time, you're likely to make lots of mistakes simply because talking has to occur at a certain pace to be interesting. If you chat online, you have time to think things through a bit more carefully. This will later help you increase fluency when you talk.
You expose yourself to real Chinese. If you study a lot, especially if you study from home, it's likely that most of the Chinese you see is textbook Chinese. There's nothing wrong with that, but it's certain that the material has been carefully selected for you as a foreigner. On the internet, you get the real thing as it's really used. This might be a shock even to fairly advanced students.
You can focus on communication instead of arbitrary practice. In most classroom situations,we focus on completing exercises, understanding concepts or writing exams. We could say that form is more important than function. When you chat, the opposite is true. Language is communication. Few people will care about your grammar, but they will care about if they understand what you say (and if you understand what they say). This is a valuable shift in perspective.
If you've visited China, Taiwan, Singapore or you've made Chinese speaking friends in some other way, gaining access to a broad variety of social media users is not a problem. Focus on people whom you either like a lot or can help you with your Chinese. It's usually easy to figure out who are good at explaining things for you and who aren't so good, just give it a try.
Once you have built a small network of people you either like or have something else to offer, you just need to make sure you spend enough time to maintain contact with these people. Perhaps you won't write a lot each time, but if you write a few sentences to each person in a small network every day, you might end up with writing a million characters a year!