based on my experience..you should know of its grammar construction coz it's a bit far from english...subject-verb agreement and it's particles like wa, no, o, ni are essentials too.. you need to be focused there and on tenses too..

self studying..hmm.. i read a lot of books, translations..watching movies and j-dramas, specially in nihongo. Sometimes, i study korean kasi i'm teaching english to koreans..hehehe, pero what i really want to be fluent is japanese, mahilig kasi ako sa anime.. anyway, nihongo is quite different in English yet quite alike, gets mo?! kasi ganito, ang japanese construction of words kasi, para ka lang nag aaral ng English, yung verb nga lang laging nasa huli.. but i really enjoyed studying japanese. One factor is i was employed to a japanese company last year. Nagamit ko talaga sya in some ways, specially pag may mga arguements kami ng mga japanese boss ko! ^_^ sometimes, we are debating for one whole day, and i'm using english-japanese phrases every now and then. So it really helped me to adopt their language more because of that, and i am so happy, feeling ko alien ako! hahaha, You should try to talk nihongo once in a while, kunwari yun ang English mo.. Bazta, ang nihongo parang english din yan in some ways, na parang hindi. You don't have to compare nihongo to english, alike. They don't have Future tenses instead they use the same present tense on verb... 3 things to remember: 1. READ, nihongo has it's own pattern.. 2. Explore and study.. 3. watch movies/dramas/ anime.. 4. Talk!! you have to implement what you have learned, diba?! hope it helps...mata atode! ki o tsukete..^_^