I have a tip that goes along with my Middlebury bias, which I’ll just throw out here real quick. The Middlebury folks seem to think that the more you use a language, the faster you learn it. So, if you could have a conversation in English it’d be much better to just have it in Chinese. They also had some research there which indicated that people with the language pledge underwent some temporary cognitive changes, that the native language has to be (rapidly) re-learned after study.
This is fairly simple, just take advantage of your opportunities to speak (and listen to) Chinese to the fullest, and create opportunities where you can. Speak Chinese with your classmates, and make Taiwanese friends. At Middlebury/PiB this led to huge speaking proficiency gains. Several ICLP students think I am absolutely insane for speaking Chinese so much. They think it is either inconvenient, or unnecessary, to speak Chinese outside class (some, even with Taiwanese friends). But then it’s the same students who think it’s so strange, several months later start complaining that they haven’t made any spoken Chinese progress, only reading/listening progress.
One blog by a former ICLP student (stealthchinese.wordpress.com/) estimates that an average immersion program student each day has “25 minutes to speak [Chinese]” - about 2 hours a week. I have about 24.5 hours of out-of-class conversation, half listening and thus building up my understanding of word usage: I heard 弄 (nong) used over a hundred times in maybe eight different contexts continually hearing new usages, and speaking and thus putting my vocabulary to real use.
To take this further, find people who share your intellectual interests and talk about these sorts of topics with them. I for example like politics, history, literature (in China, Lu Xun, Hu Shi et al.) economics, cooking, law, ethics, and philosophy. Your interests will often collude with what you’ll use the Chinese for, thus building up your ability in your field in addition to working on your vocabulary. You’ll also find where you are lacking - I ran into, how do you say “billable hour” in Chinese? That is a pretty serious gap, in my opinion, not knowing how to say billable hour. Watch movies with your friends, then talk about those movies, talk about news, go to art galleries and interpret art. (art is especially good, pointing to the anvil "what’s that called?.. anyhow, I think the anvil here is used to express…)
Finally, read about stuff that interests you. Read a lot of it. Develop a hobby in reading Chinese. I read a survey of people who’d reached the upper ends of the language scale, and all of them said they took reading very seriously. You won’t learn how to discuss economics by watching It Started With a Kiss.