I sincerely make every effort to speak standardized, by the book radio transmissions. "Passing one zero thousand for one three thousand", for example.
It's a good system, and the vocabulary of standardized ATC words is really quite small. Never say, "Lookin' for lower" but the correct, "Request descent".
Some time ago, I was furloughed from my US airline job and worked for five years, mostly in Europe, but a lot of Asia and the Middle East. It was so nice to come back home to US ATC's and native English speakers.