Many of my students ask me to work on pronunciation but it not feasible to address all students’ pronunciation problems of a whole class as each language speaker has specific problems. I usually suggest that students take one on one tutoring to work on their accents. Many language students are very self conscious of their accents.
If you want to pick out your own dialect of English, you can in fact make this wish come true! You can select any accent that you want: Australian, Cockney, Deep South, Dialects of British Isles and Ireland, Aafrikaans, South Boston, are amongst the offerings online. Paul Meirer has trained many people to speak with different accents and has a website that offers a wide range of English language services (http://www.paulmeier.com).