> Try dubber ducking to yourself out loud new concepts/things (in English) you've learned, even better if you could find someone to listen to/explain to.

This is something I occasionally do. I'll better do it a bit more often.

> (I don't see myself ever doing this but worth suggesting nevertheless) Start a podcast or vlog discussing technical topics (without scripts.)

This could be something that wouldn't need another person to perfect my language. I'll see if this helps. Thanks a lot!