First of all, language skill is always a must for a translator, both the source language and the target language. You might think that as a Chinese, I would of course be good at Chinese. But this is a wrong concept. Sure we all can communicate fluently in Chinese, but oral communication and written skill are totally two different things, especially as a translator, sometimes it is difficult to find an equal sentence for the one from another language. It is even harder to translate it both accurately and beautifully. Sometimes I have to do some evaluation work for some non-Chinese speaker clients. They would ask if this translation has any accuracy problems, grammar errors or terminology issues, but actually even it does not have any of the above problems, it still does not necessarily mean it is a good translation. It can be simply not native enough. So that is why we have to polish our language skill all the way along this path.
English skill is much more difficult. I always insist that a translator should only translate articles of other language into his or her mother language, not the other way around. Because even a native speaker can not always make a good translation, let alone a second language learner. But if we have to, we should translate it as native as possible, and choose proper words instead of pick those randomly from dictionaries. Plus, we have to improve our English skill so that we can understand the source article thoroughly.
Another thing we have to learn is the enormous knowledge of each field that we need to translate in. Translation is not just an art, It is also a technique that we need to learn constantly. You need to know the field of the article that you are translating well to do a good job. As I am doing medical translation, I always find new terms and knowledge that I did not know before because it is such a big realm that even a doctor would not know everything in every subject.
This is why we need to learn, but it is also the reason that we need tools – searching information from the internet. The things that we already know are limit, but with the help of the internet, we can almost find any information that we need. Of course this requires some skills, too. So learning to find information is one more skill that we have to improve.
Last but not the least, learn to use various CAT tools. As all kinds of CAT software updating all the time, translators need to update their knowledge about those tools, too. Making good use of a tool can help you translate much faster and better with less effort.
Life is a learning process itself, this is true in translation, too.