It’s the same technique I’ve been using for Russian since the start of the year, that is, watching YouTube with dual subtitles with Language Reactor. I try and read the Russian subtitle, and when I don’t know a word, I quickly scan the English translation line. For my Russian, after 50-100 hours of beginner and comprehensible material at the end of last year, I moved onto lower intermediate material (Russian with Max) for 40-50 hours before moving onto native material. For the last three or so months, I’ve watched YouTube videos only from the interview channel вДудь (link), discussing politics and life. Now I’ve moved onto the let’s play channel MrLololoshka (Роман Фильченков) (link). I do very little repetition, as keeping with the same author and the same topic, the most frequent words commonly repeat. These videos I watch are word-dense with 8k-10k words per hour (130-160 wpm), as @ericb100 was mentioning. They are also improvised conversations, which is the vocabulary I’d like to focus on. As you and @LeifGoodwin were discussing attention, I am only doing active study, and I find watching the video of the interview or the let’s player at the same time highly focusing. I also get visual cues to anchor certain words to emotions and images.
So all in all, I consider I’m getting high quality (with high focus and visual cues), high quantity (word-dense, no faff with making definitions, etc.), challenging (native material), and highly motivating (interesting content) study. I’m focusing on conversational vocabulary acquisition, but simultaneously improving my listening and reading comprehension. And I know it works, as I notice all these things vividly improving. (I’m currently at 270 hours of recorded listening, 90%+ would be reading while listening, and 50% of it would be from native material.) I even had my first full-fledged conversation for over three hours the other day, chatting with a native Russian speaker I met. I’m very satisfied with my current approach.
(As mentioned before, I consider this approach to be appropriate from the beginner level to perhaps B2+/C1. Once you get C1, this approach is no longer as effective, as it’s too easy. Also, once you get to C1, vocabulary may not necessarily by your biggest weakness, so best to do techniques to directly address your weaknesses.)
Honestly, I’m almost feeling as if I have perhaps more progress with a similar time investment than I did with Italian, a language with more cognates and which uses the Roman alphabet. (My approach for Italian was reading while listening on LingQ, lingQing words, and being more progressive in my content selective, plus ‘passive’ re-listening.) It’s hard to compare, but maybe I should see if I can find a test. If I can converse with someone for over three hours about a range of topics, I’m at least A2.