I've been on the internet for quite a while now, I can safely say. I've come across countless of interesting threads from sites like Quora, Reddit, or here. I've also encountered many users who are really good in their English, judging from how they present their opinions or questions.
This is one of the examples (first answer by Ben Kovitz or the question by Canada Area 51 Proposal, they display abilities of good writing)
In general, I can grasp what they're trying to say. But, when in comes to writing, I just can't. I have many ideas, in fact, great ideas. But, the problem is that I can't put them all in sentences and paragraphs coherently, let alone writing good essays.
I would like to write very naturally and fluently like how people on the internet do.