Shadowing is rather simple but highly effective. The way i did it at least, involved ripping the audio from tv shows in French. And listening to them on my phone as i would music, while trying to say the characters lines with the same tonality, pronunciation etc etc.

The objective is to try and be as close as possible to the recording. You would use the same recording/s over and over again. To try and hit all the right notes when it comes to expressions and all that. This is a sort of dry run of having fluid conversations.

Do this, everyday for an amount of time that works for you say 20 minutes or so while taking a walk, or while working. It really helps, and to me somehow connected the words i "knew" but my brain never detected when someone said it in a tv show, movie, podcast, let alone a youtube video or something informal like that. Shadowing made things click for me not just in pronunciation but in listening.

Its weird to explain it, as you kinda have to go through it. Its a minimal task with lots of benefits.