This one works very well if you’ve got 3 and more target languages. I’m going to use an example of three for facilitation, feel free to adapt to your x target languages! (I personally use French, which is my fourth and Irish, which is my seventh! And I’m saying that in case someone wants to be language buddies)
Translate from a target language into another target language!
It does sound pretty obvious and I’ve done it so many times before, but I’ve always used a language I spoke pretty well and a language I didn’t speak that well. But why not use both of the languages that you’re just learning?
Take an easy text. Like a song, a children’s book excerpt, a user manual (great for imperative in case your TL has it), a website, some random chat... the text should ideally not be very long, half a page or about 250 words is great for B1/B2 level.
I would usually prefer to use the language I’m better at as the language I will be translating into and the language I’m not that great at as the source language. In the analogy, it would be translation of a text in L3 (third language) into L2. Now, you should not be using your L1 or your first language or any language you know very well to help ‘bridge’ the two. Try to train your brain to only work with the two. Google Translate should be pretty helpful, you can only set it to those two languages. Of course, you’re allowed to use your L1 occasionally, maybe for checking or if you’re having trouble translating. You do get the idea though. Try to only use the two target languages, only use L1 if you really need it. Or maybe you’ve got another TL that you’re pretty good at, maybe you can try that one.
You’re also going to be training your brain not to automatically translate everything you read into your first language, which is very useful down the line. Hope you can use this exercise to improve your target languages, good luck!