I've been studying Japanese for about 3 years and I'm coming up to take the N2 in December. Vocabulary, kanji and reading are generally ok for me and I have ways of practising those that are pretty straightfoward and have been effective so far.
But for grammar I'm a bit stuck, I think because unlike vocabulary where it's always the same even as the words get nicher or reading where the text just gets harder, it feels like with grammar because it's a pattern rather than just a word it feels so much harder to commit the nuance of how to use it to memory as the use cases become increasingly rare. If you learnt how to form the past tense from Genki 1 you could maybe see it being used every other sentence but something like に限らず how often will you get reinforcement naturally in text?
I'm using Try N2! and Shinkanzen Master and have finished both. When I go over each grammar point I sort of feel I get the point but two weeks down the line I'll forget half of them.
Part of the issue is that the grammar points at N2 can sometimes be such niche points of speech that you could read for hours and maybe find one instance of a specific grammar point (like how often are you going to see はもとより realistically?). Not that reading is bad but in terms of time it feels a lot more time inefficient for committing niche grammar points to memory especially if you're working full time on the side.
For vocab I get around the nicheness issue by just having flashcards with SRS, I've thought about doing that for grammar but not that sure what it'd look like, would be interested to hear from other people about methods they've found successful :)!
by CoronaDelapida