At the beginning of the year I thought that I had a good english level, because I could understand close to 70% of what I listened to in youtube videos of youtubers I liked. However, my own perception of my english level was shattered when I had a job interview in english, and the woman who was interviewing me decided to cancel the interview because in her own word I didn't "express myself properly in english". This was the inflection point, and the moment in which I realized that I needed to improve my english fluency.
So, I decided to look on the internet for ways to increase my understanding and speaking abilities. That's when I found this youtube channel by A.J. Hoge:

He uploaded a video in which he explained the repetition method to learn English. That method consists on watching a 5 minute scene with subtitles multiple times until you have memorized every word that's said in it. After you have memorized every word, you watch the same scene again multiple times but without subtitles. This way, you can train your listening skills so that it gets easier to understand what people are saying.
To be honest, I didn't think that this method would improve my English, but I tried it anyways. I picked the tv show Better call Saul, since it is my second favorite after Breaking Bad, but I wanted to watch that story in chronological order.

After watching the first 5 minutes of the first episode I recognized most words, but I don't think I would have gotten all of them without the subtitles. But, even though I already knew most words, there were still some I had never seen such as:
- Cornered
- Primal
- Laundering
- Atone
- Seedy
Doing this exercise is extremely boring, so I was lucky to pick a tv series that I liked a lot. I needed to persist with it since I knew that I needed to have a good English to get a good job. I did this exercise for a month and by the end of it, I have watched all of the first season of BCS.
Three months after that, I decided to test my English skills by taking the IELTS exam and get certified. I registered to take the exam in May of this year and the results speak for themselves. I got 7.5/9 which means I got the C1 level in english. This shows that with patience and discipline, this method works to learn any new language, not just english. So my next step, since I have always wanted to learn german is to apply this technique for this new language.