Stepping up to my next level of English

This might be really a typical question for a non-native English speaker he who wants to step up to a higher level of both, speaking and writting English. And I'm actually one such speaker. such a one. I'm actually a freelancer working online. But I'm not a native speaker at all. I believe that the best way for learning English is using it in the real world, communicating with a real native English speaker.

Actually, my freelancing experiences did help helped me a lot to improve my English. And, I have found that while discussing with my clients about the work, they normally don't/won't point out my mistakes of English. I think, mostly, I can clearly express what I want to say. But I have no sense/idea if what I wrote or said is good from the perspective of a native speaker.

This is the major reason I'm here on italki, looking for more native English speakers as friends.