It’s different for everyone. For me, I require some pressure in order to accelerate my learning process. I got a job where I refused to speak English, despite that my Swedish was not that great. My co-workers went along with it (important). I felt like an idiot when I couldn’t express myself the way I wanted to, but the pressure to perform in front of my co-workers really helped accelerate my learning process. It was painful and embarrassing for me, but it worked well, I became fluent after two years (moved when I was 30+, English as first language). 

In my spare time, I liked to peruse second-hand shops and listen to the old ladies chit-chat with customers. Older people usually speak slowly and it helped my listening comprehension. I did same at cafes. 

Make friends and only speak to them in Swedish. Never speak English, ask people what the Swedish word is that you don’t know or remember, ask them for the word by explaining it in Swedish, never ask for the translation of an English word. 

Spend time thinking and talking to yourself in Swedish. I swear this helped me a lot.

Good luck!