Practice Chinese writing, reading and listening.
This helps to acquire a good foundation in writing and reading. The repetition in writing of the basic characters is paramount for learning and memorizing new words. And, to me, it is kind of meditative: grab some tea, put some Pipa music on your mobile and just practice writing some characters.
Practice on a regular basis.
Daily practice is most advised. Moreover, in time, it will become another daily activity, thus easily linking new concepts and words with already known or reviewed ones from the previous days.
Grammar.
Yes, grammar is very important. This is the key to recognizing patterns in speaking, listening, reading and for developing good writing skills (in addition to vocabulary, of course).
- I know grammar is not the most popular subject in school, but it is VERY IMPORTANT. Grammar gives you a deep insight into the language you are learning. Moreover, the more different a new language is (with respect the ones you may already know), the more helpful grammar is to learn and understand the patterns of the new one.
- A good knowledge of Chinese grammar will also help you to think in Chinese when you speak/read/listen/write in Chinese, thus avoiding the misleading (and usually full of funny “traps”) translation path. In other words, when you speak English, you think English, right? Well then, do apply the same with any other language: think Chinese and you will speak Chinese. How to do this? Well, in time you will find that you can understand what you read/listen without translating into English: that is the moment when you think Chinese. This takes time and persistence, of course.
The next two are complementary, and very enjoyable in my opinion, especially the last one (trips to China):
Learn about Chinese culture and history.
There are plenty of books, movies, documentaries (I strongly recommend the BBC series “The Story of China”).
Trips to China.
It is one of the most thrilling experiences about learning languages. This will put you on scene. Your senses will adapt to an environment where everything around is in Chinese. This is like running a marathon after a long training and finding out that you can really run. 🙂