Chinese language learners, what is your favourite Chengyu? 
I remember learning this one in class: 虎头蛇尾 (hǔtóushéwěi) literally “tiger’s head, snake’s tail” to say that something got a strong start but weak finish.
Also, I really like 自强不息 (zìqiángbùxī) that means “constantly strive to become stronger/improve oneself”.
Any 成语 you learned you’d like to share?
Nice topic, I’ve been trying to shoehorn these 3 into my conversations lately:
独一无二 means unrivalled or the very best
莫名其妙 means baffled-super confused
不可思议 means unthinkable
These may actually just be 4 character words rather than Chengyu but I wanted to share as I am hearing them more and more in my podcasts and they are really neat ways to level us up.
I’ve used all of them recently and on more occasions than not, the Chinese speaker says “Ooo nice vocab!”
I’ve always liked the good old 入乡随俗 “when in Rome”.
I’ve been using 对牛弹琴 “pearls before swine” a lot lately.
鸡毛蒜皮 “trivial matter" is a good one.
”Work hard play hard“ my favorite 英语成语 
This due to the LTL lesson by any chance? I’ve not taken it yet!
Yep. That’s a good class, with a story to associate to the 成语. I had originally skipped all the “writing” classes, but now I’ve going back to do them. I don’t handwrite, but there is still a lot of good stuff in those classes.
My all time favourite is 白头到老 meaning to live together until the white hairs of old age show up… for me it’s so cute🥺 and it makes me think of my grand parents🥰
Another one I love is 雨过天晴, meaning “silver lining” because I like to think that every bad situation can change for the better!
These are great!!
Do you manage to use 成语 a lot while speaking?
I still don’t feel confident enough to use them to he honest 
There is an easy one that everyone can use:
马马虎虎 - means so-so.
你怎么样？ - 马马虎虎。
I love this one! I think it was the first one I learnt 
Like Max, I try to shoehorn them in!!
My favourite one without a doubt is
趁火打劫 chènhuǒ-dǎjié
which more or less translates into “take advantage of fire and plunder”, i.e. profit from misfortune.
I love it just because it’s so cynical and dark, but it makes me laugh