jtalkonline.com/boosting-your-japanese-ultimate-guide-for-intermediate-japanese/
I previously wrote a very, very long article all about study resources and tips for beginners looking to learn Japanese. But there’s not really anything like this for intermediate learners.
Resource lists and enginesCourses, textbooks and schoolsGrammarTextbooksJLPT N3JLPT N2Listening practiceIntermediateBeginnerJLPTFreeSpaced repetitionExample sentences