Practice shadowing

I mostly speak English at work and that's it. My colleagues are nice people but they ask me about the word I said a lot and a friend of mine who's really good at English told me that my pronunciation makes her ears bleed. She also told me about shadowing.

That's when you try to repeat and immitate somebody else's speech by repeating after them trying to follow their words. It's simple but seems genius. I'll try to do it 15 minutes a day and see if I have a result.