Improving language abilities past basic proficiency... (without a native speaker)

I have two target languages at the moment (French and Hindi) that I want to bring myself up to a higher level of proficency on. In both, I can understand dumbed-down texts and can construct straightforward sentences, but have trouble expressing or understanding complex thoughts. Basically, I’ve passed the point where there’s much grammar to learn per se and my biggest obstacles now are vocabulary, production/comprehension speed, and idiomatic expressions / discourse markers. What’s the best way to go about improving? I’m a linguist and learn best through that lens. One of my biggest problems in comprehension is understanding individual words but not being able to grasp the meaning of the phrase as a whole (whether because it’s idiomatic or because it’s syntactically or semantically tricky). I’m lucky in that there are a ton of media in both of the languages I’m working on, but one problem is that if I’m watching, say, a movie, I tend to get annoyed at the fact that I can’t 100% understand it and get caught up in the details rather than letting the language wash over me.

What do you do to further your proficiency? For any language, of course. And I’m ruling out talking to a native speaker because obviously if you have access to one, conversation with him/her is one of the best options.

Well all I can suggest is find some chat rooms for the languages you’re learning. Of course you’ll probably just become well versed in a foreign chatspeak… but that’s something! Also, have you tried seeking out an online penpal? There’s lots of websites out there to connect people who want to do language exchanges. Well…actually the only one I know of off the top of my head is worldfriends.com however I’m getting more creepy old men who want to be ‘friends and more’…

Edit: I win at reading comprehension. I just saw your last line about a native speaker. But if you don’t like movies/tv I don’t know what to suggest outside of literature. Have you tried translating song lyrics from their native language into English? I always found that entertaining and educational.

Try getting music in those languages and listening to them a lot.

You can also trying getting movies in those languages that have subtitles in those languages and translate them into English.