The easiest and expensive cheapest way to polish your English pronunciation is through "SINGING". Not only you have fun but it helps to improve your speaking production. Start with your favourite songs. Get the lyrics and understand the messages. Next, pick some words or phrases from each song that you want to learn. If necessary, look up in the dictionary for the exact meaning. Last but not least, listen to the song and mimic sing along. That wouldn't be a problem at all, right?