My English level is between B2 till C1 and If I wanna give you guys some recommendations , there we are :
1. The most essential thing that can help your speaking , writing and also listening is that you ought to have a completely wide vocabulary territory . When u have a variety of words in your mind , it's really easier to making sentences immediately in the way that u want and giving others completely the accurate thing that u mean.
2. You should have daily interact with English stuff(not simple ones). Like listening to music when you're fluently know the lyrics so when u hear the words that the singer pronounces them , you can identify them much better.
3. Watching movies , shows , YouTube contents with English subtitles(It's available for most videos on there)
I can go more with details but let's cut the chase cause they're my most useful personal experiences.