Stop using Chinese all together. Watch TV with English only programs and read english articals/books. To be honest with you, it takes lots of hard work and time to do this, but the reward worthes the effort. It worked for me.
My english is still not good, but it is good enough for me to go to court and get my traffic tickets dismissed twice without a lawyer. At home I can help my 9th grader in writing, math and physics, all in English. At work, I am confortable to write emails to spam 2000+ people including our team SVP, to give status and instructions. This summer I took my kids to the national history museum in Beijing, it is a pleasent surprise that I can translate the description of historical events between Chinese and English, much better than the offical translations there.
