In addition to practice (which many here have suggested - and they're good suggestions!), it would probably be helpful to get some feedback on your writing as well. I find in coding at least (the closest comparison I can make since I'm a typical American and only speak 1 language), the absolute best and most "rich" learning is done when someone corrects/improves work I've already thought about and tried.

Not in an insulting way of course - just in an improving way. And on that note, I'd be more than happy to give you feedback on your posts & comments here if it would be helpful and not offensive. In public or in private. Just let me know!