I have been living in an English speaking country for six years now. My English has improved in the meantime, though the progress has slowed down in last few years.
I think the reason is my laziness. I have bad habit of not finding the dictionary when I encounter new vocabularies. I just guess and then forget. I probably have to use my dictionary more often. (I bought a fancy electronic one few years ago and have been ignored it.. sorry dictionary.)
Another thing I will try is to post more articles on my blog. I don't promote my blog to many people because I am shy - worried about my grammar - but I enjoy writing. Hope I keep this resolution for a long time.