I became fluent in Russian after 2-3 months of living in Moldova. I had a crash course in Russian beforehand, but couldn't say a whole lot more than basic phrases before I got to Moldova and couldn't understand much either. Obviously you need to study (grab a good grammar book). But I ended up studying less than an hour a day when I was there. What I did do was speak Russian as much as possible. You have to force yourself to use the language. What set me apart from the people I was working with (in terms of using the language) was that I was not afraid to fail. I just continued on and tried my best. I gave myself no chance to fail. If you aren't living in country that speaks the desired foreign language it is a lot harder. I took French in school for over 10 years and another two years in university and I still can't speak it. My grammar is very good in French and I can read it fairly well, but can't speak much.
Started "French Immersion" in BC in kindergarten, then in Grade 4 moved to an entirely French school in Ontario for two years. After that, more immersion. Missed two years of French classes in highschool, so was catching up when I started university. A "minor" in French (I think I was one course away from getting it) fixed that nicely. I consider myself fluent, but I don't get enough practice to be able to use it professionally.<p>Over the last two years I've been immersed in Tagalog, with the help of one introductory book (basic vocab and grammar). Tagalog is easier than French so far because people speak mixed English and Tagalog (Taglish) all the time. I can follow conversations 50% of the time due to context and the odd English word. That's letting me learn organically without really trying. Next step is I need to spend a few minutes per day going over phrases from the <a href="http://tatoeba.org/" rel="nofollow">http://tatoeba.org/</a> database.<p>EDIT: I use French because "Canada", and I use Tagalog because of family.