sharing my $0.02 here.
for me, i think motivation is very important in learning a language, japanese in this case. i have seen too many people/colleagues who learn the language just because they are in japanese companies, and need to for their work. and almost all i know, stopped classes after basic, or at the most intermediate level. they find that even after going for classes, it is still not enough to communicate with the japanese, and go back to using english. and many of the colleagues can speak/write decent english, so in the end there is not much motivation for them to continue the language and drop out soon. and out of working hours, there are no chance / they do not immerse themselves in the language/culture, therefore chances of learning are very limited.
for me, i started listening to japanese songs, watched j-drama when i was in poly, used to listen to the whole japanese cd the whole day till i could memorise the songs even though i had 0 japanese ability. for me, that was a very good way to learn the correct pronunciation. i see so many people who have N1/N2, but their pronunciation is way off.
and after NS, i went to Ikoma in 2005 for full time classes, from the very first biginner course all the way to further advanced, and passed my JLPT 2 in 2006. Took Ms Bullet train's JLPT 2 prep class and her further adv classes. she was so fast in class that there is no time for you to think of anything else but to just listen to her. her mentality is, if you are already in my JLPT2 class, you should already have a certain level of japanese ability, and since this is already level 2, there is no point to go easy on you and to expose you to a speed nearer to native speaking.
by the way, she is in Ikoma's office in Tokyo now, helping out in office and arranging courses for those who want to go to learn in Japan. and oh, her full bullet train speed is even faster when she talks after classes.
i then started working in a japanese company, used japanese and although i could communicate, business japanese was very diff from that in language schools. i switched over to part time course after working, and got my JLPT 1 only at my 3rd try. and also took the previous BJT.
through ikoma and work, i got to know more japanese friends, and also got to know my wife who also had her circle of japanese friends/colleauges, thus expanding my chances of usage of japanese. she's an even more japanese maniac than me, speaking more and and listening to more japanese than me. watching japanese dramas and variety shows together at home, and with her correcting my japanese at home helps even more.