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Visual language learning.
Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.
I myself have been using the flashcard app Anki, which exists for (and can sync across) Android, iOS, web, and desktop applications. It's free on all platforms except iOS. For just drilling, this indeed works very well, but it does take time to make the cards yourself. I've been slowly learning Persian for some years now, and I have about 2000 words in my collection.