Most people who come off as eloquent in english have spent a lot of time not only writing but also reading. Reading encourages passive learning of language patterns, and reading the works of talented writers (even without analysis) can lead to learning some of the skills that those writers use. (I'd be surprised if this were not also the case in your native language.) If you feel like you can't get enough practice sp…
Read writers of different styles, and read poetry. At the risk of leaving out hundreds, off-hand, read Betrand Russell, Nabakov, Dylan Thomas, Louisa May Alcott, Kerouac. (Try to ignore the fact that Nabakov wrote exquisitely well in more languages than most people speak.)
Read these works aloud, because they sound differently than they scan on the page. Especially if it's something you like, or something that you find hard to read and parse.
Emulate each style. Try copying their words verbatim, because you'll realize things that are easy to skim over when reading. Then try writing something new, but using their style, acting out their style.
Realize that some writing is not meant to be accessible and assume that there will be writers whom you respect, but whose writing styles you don't like. Understand why you don't like those styles and how to avoid those forms -- what did they do and how can you say the same thing but not in that voice.
And, of course, write as well. Write a lot.