The following site is very interesting.
The International Dialects of English Archive
Test your ear
" a non-regional style of American English"
Which do you prefer, Received Pronunciation or General American?
Or, which “dialect” do you prefer?
Record your voice and compare with a native speaker, also be very immersed in the language.
It needs tons of hours, is it worth it?
Good question. In general, I’d say it’s not. But westerners learning a tonal language really should record themselves to get a grip on their tone errors. It’s a very powerful study method, that beats even getting corrected by a native speaker, imo.