From my experience there are methods that are even better than listening to movies and song because... People speaking there are never perfect. They just have... their own accents. So it can be pretty ridiculous to study English by, for example, old cassettes and CD's... Never helped me to get a better pronunciation, just managed to better differentiate bad accents... The best option in studying languages is getting help from professionals. It's true. Like, I've been getting help with my homework on https://homework-lab.com/, was really useful when I was struggling and couldn't find mistakes myself. Also, it's cool when it's possible to study remotely. So, I'd say the best advice is to never try to do everything on your own. You could just keeping bad habits and not able to realize your full potential.