>>296
That's so nice of you saying that, but actually my writing skill is very limited unlike you might think I am.
That being said, since you asked me so politely, I'll try my best to answer them.

1) I'm 100% Japanese, back in college I used to stay shortly in Canada for learning English though.

2) As for this part, there's not really a special technique or anything.
I just always read/listen VERY carefully to movies, passages, books and podcasts, etc. sometimes again and again.
As I was working on that, you may or may not notice there's a pattern they follow in most of their lines.
I analyze and learn them by words to words, rephrase them in my own words when writing. It's actually that simple.
Even when we speak Japanese, you can totally see that almost everyone follows the similar sentence structures, right?
Those ones that don't quite fit in them will sometimes sound a bit awkward imo.
Phrasal verbs (such as "walk down/stand up") and rephrasing & avoid using too many of the same words in one sentence also help you in this.

In conversational English, I think it's very important to pick out the words that's commonly in use, not some random words from your dictionary;
always remember you don't write in a literal translating way, because you can't be sure that they sound right.
Whenever you feel you can't find the right expression for your ideas, just look for another more natural way of saying them.
And most importantly, immerse yourself in English. Only this will nurture your sense of what's right or wrong.
Double the amount you see English everyday if you think your English is not good enough. (Personally I don't think you need to)

Your English is very good, so whatever you are doing now, just keep it up. Maybe that will get you to the point that you are going for there.
I think that concludes my little pieces of advice, I hope this will be of some help.