In my opinion,
i think the key way is more watching, more listening and more usage. Any opportunities which can be replaced by using english instead of Chinese should never be wasted, for example:
1. reading original foreign library document instead of translation edition
2. write english commit message
3. use Quora instead of Zhihu
4. answer questions in stackoverflow.com
Grammar, vocabulary are unworth for special learning, but it's okay to query them at some time depending on your demands. never afraid to use incorrect english, after all, English is just one way to express your thoughts and get understanding of others, and it’s very hard to reach the native level of english people in domestic, so get free to use english.
In short, try to make learning routine and integrate it into every aspect of life, instead of studying it exclusively
I use google doc to write down this text, google doc help me to correct simple grammar errors. Hope these can give you a favor ^_^.