I don’t review flashcards. I think, it’s a very time consuming activity. I find it boring. I also use the Steve Kaufmann’s method to mark a word as “known”. If I think that I’ll remember it when I see in a similar context, I turn it to “white”.
BTW I think that listening is as effective as reading to learn vocabulary. What I find to be highly effective is to listen to something and read the transcript at the same time, then listen to it later to see if I can understand it better. Reading and “listening and reading the transcript at the same time” are two different activities IMO. The latter is highly effective.