I am now in benkyō mōdo for the N2 JLPT. These are my three main methods of study.
Not a bad textbook. It has EN, CH and KR translation. It covers a pretty good range of vocab. It’s designed for 8 weeks of study.
My first Japanese ONLY textbook. It covers the grammatical nuances and lots of convenient structures that are and aren’t used in every day conversation. It will definitely mature your Japanese. I highly recommend this textbook.
Another major recommendation if you want to understand real Japanese. Kanji is a vital part of the language. It’s a lot easier to learn vocab if you know kanji.
I’m planning to take a practice exam sometime before the real one in December. I remember doing this was a big help when I took the JLPT N3 in 2006.