Read a book that matches your taste, like: folktalss, biography etc.
whenever you find a hard word, use a dictionary. It's pretty simple.
I got my accent from Disney movies, so that helps too.

More gaming I would say, atleast that's how I did it.

Watching movies/ tv series and gaming.

For improving your writing use books and more books. And for pronouncing and talking pretty much anything else, movies, cartoons, games...not that hard. And you should make sure you talk on English with someone or even yourself when you comment on something or shout

Games and music .. Worked for me ..

TheMiinuko wrote:

Games and music .. Worked for me ..

I second this.
I used to listen to (good) rap on a religious level! I learned some pretty uncommon good words there.

Hope This Helps

I think it would be a lot useful when you game with a group of english people, i talked with my ex just for fun in english and we learned a lot during these days