The good news is that there are effective (and simple!) language learning methods, it’s just that very few people actually use them. Here’s the tried and trued formula that is reiterated again and again by the vast majority of successful language learners:
1) Maximize Input
Get as much meaningful and interesting input as possible. “Meaningful” here means that is just an itsy-bitsy bit above your level of comprehension. And the more interesting the material, the more likely you are to continue listening or reading (and repeating the process again and again and again.)
2) Use narrow listening & reading
“Narrow” here means that you listen to or read a variety of articles on the same topic. This allows for sufficient repetition without boring yourself to tears. If you have access to native speakers of the language, you can conduct a simple interview with a few different people. Chances are they will all use a similar set of vocabulary again and again since the context is constrained by the questions you ask.