While travelling I picked up really useful Chinese. For some expats and other laowai these might be obvious, but I found this to be very useful.
打包 (dǎbāo) - Take Away
With my girlfriend we'd often go to the Xiamen University canteens and order some delicious noodles, but because it was so ridiculously hot, we'd often get takeaways to go sit in air conditioned dorm rooms. I used this numerous times, from fast food to noodles shops.
拉 - 推 (lā - tuī) - Pull- Push
Written on almost every door, these two characters indicate whether you should push or pull. So at the risk of embarrassment I had to learn these two really quick. Remember them. They are everywhere!
不用 (bùyòng) - Need not
I knew this before going to China, but this negative verb construction took on a new use in China. I think this is almost the closest you can get to saying "No, thanks" in Chinese without the extremely awkward literal translation “不，谢谢”. I used this a lot, for instance at convenience stores when they want to put something in a bag, you respond with 不用 if you don't want it. Mostly any request that you want to decline politely you can use this.
打印 (dǎyìn) - To print
While booking flights and hotels, I had to print e-tickets. Most Internet cafes or hostels have services, but you often need help. Thus 打印 is a very useful verb to know when you are travelling. While in Xiamen the one Internet cafe did not have printing services. So I asked where I could go. Luckily, just downstairs there was a printing/copying shop. Just look for big signs saying "打印" and you are set.
押金 (yājīn) - Deposit
Booking hotels or apartments almost always comes with a deposit. Thus, knowing this word helps a lot. It acts as a verb and noun. When booking my apartment in Xiamen, they shoved a paper for me to sign. I asked what it was, but they responded to quickly and couldn't understand. I read the slip quickly and noticed 押金 and my mind was at ease.
免费 (miǎnfèi) - Free
If you are a traveller, or anyone really, this word is the word to look out for. You see this quite a few times, especially when booking for hotels. They often say 免费宽带 () which means free broadband and who wouldn't want that. I also saw it on a bank notice 开户免费, which you can open an account for free.
朗姆可乐 (lǎngmǔ kělè) - Rum & Coke
After getting tired of beer, I was craving an alcohol mix. Usually in South Africa we mix brandy and coke, but the closest I got to that, was rum & coke. This was typed on a menu. Note that both 朗姆 and 可乐 both sound like rum & coke. So if you are craving rum and coke, 朗姆可乐 is the way to go.
信用卡 (xìnyòngkǎ) - Credit Card
Once again, if you are travelling, this word becomes very useful. I often tried to find shops and people that used this. However, very few people used these in China. In the last hotel that I stayed they asked me for this as a deposit and possible damage covers. Very useful word.
充值卡 (chōngzhí kǎ) - Recharge Card
Another card. Using a Chinese sim card is necessary if you don't want to run into massive roaming costs. However, when your airtime runs out you have to recharge. Just go up to mobile vendor, you'll see signs around, then ask for 充值卡 and how much you want. Just be sure to ask for the right operator too. I ended recharging 50kuai cards quite a few times, 'cause sending texts back home is quite expensive!