Studying between reviews?

For vocab, you should look into, although I do this kind of stuff on Anki, with Core 10K breakdown deck.

This one is EN–>JP, plus I always look at goo dictionary for most entries; and sometimes, thesaurus (類語辞書). I actually remember the example sentences.

Ah, yes. WaniKani’s provided 1-2 example sentences are not enough and usually not covering all definition; and even sometimes don’t even cover the meaning you have to type in.

For Kanji and Radical, I also drill. I used to use [Userscript] Self-Study Quiz, but now I do all of this on Anki.

The rule to decide whether I succeeded in drilling, is that I can type in answers with speed. No hesitation. 5-10 times’ repetition helps a lot.