when i was still learning english officially, my north-american(usa) cousin told me that she could only tell my accent after five minutes of talking. needless to say ive [as we say in hebrew] got a good ear for the music(meaning, i differ sounds pretty easily, god with music and such]. i personally really felt the muscles develop as i was speaking for the first years. also i am good with mimicking accents if i hear them enough. i worked with russians for two months and i could chat with them a bit... its been said here - its an innate ability, some are better and some are not, just like in everything else. a great tip i can give is to give up on subtitles,read books,hear music of the language youre learning.