I just wanted to start off by saying that I use the English language every single day, even more than I use Norwegian. Not because I consciously choose to use English, but rather by default because the amounts of information available and the quality of information tends to be much higher than what I can find in Norwegian. But recently I have started reading classics and what I noticed is that my language is actually very simple and "bland" and "colorless" in a way (atleast more bland than I initially thought it to be). Mind you, I have no trouble reading any mainstream English/American newspaper, media or any other modern litterature whatsoever. This made me come to the conclusion that reading, especially older litterature is nessecary, even for native speakers in order to broaden your vocabulary and apply a more colorful language in your daily speech aswell as in writing.
Hi again - Amir, I wish that i could read Russian, but am stuck with translations. However, you guys :) have a great theorist on poly-vocalism and the 'carnavalesque' in literature, Doestoevski and Rabelais, among others: Mikhail Bakhtin, you should check him out if you haven't already read his work, to read more into the text and poetics of your language! For english, to combat the blandness ably illustrated by SHL, there is this, https://en.oxforddictionaries.com/explore/word-of-the-day - you can sign up for a word of the day from the OED, it's an easy way to go off on a word-idea meander right from the start of the day!
Keep reading and talking about books!