Listen, listen, listen. The best advice I can give, and what helped me the most, is watching movies or shows in the language you are learning, as well as music, talking to people online via skype or in person, and YouTubers. Pronunciation is so tough to get the hang of through just reading and studying text, so listen to anything and everything you can find. Then your next goal would be mimicking them to the best of your ability, and it definitely takes practice. It took me a month to try and pronounce the word "twelve" in German correctly, but I mostly just kept talking to myself and finding videos where people actually would sound out the word slowly.