When I joined my first job in 2005, I met some of the folks visiting us from different countries for business meetings and I noticed that many of them used to say words like 'Namasate' by joining their hands and 'Dhanyavaad' in the same fashion. Obviously these acts used to impress me and at the same time I was wondering that why these folks say all these words by joining their hands, because we Indians have stopped doing that except few occasions which vary from one location to other, kind of gathering or meeting.
But one common thing is that they had done good research before coming to our country. They spent time understanding some of the common words in Hindi and cultural way of communicating those words.
During one of the my trips, my nephew said 'Thank you' to a bus assistant in Kher and she was very impressed and her smile said a lot of things. At that moment I realized that how such small words can bring happiness around you when you are travelling. So far, I had not paid much attention to it except understanding 2 words for salutation and saying thanks.
Some of these words are :
1. Hi (how salutation happens in local language and if there is any specific way of doing it. I mean any change in tone or body language.)
2. Thanks
3. Please
4. How are you?
5. How much? ( and "Too much" :) )
6. Ok
7. No (and strong No)
8. Excuse me
9. Good
10. Bye
11. I don not understand
12. Do you speak English
Apart from that it's also recommended to have a good translation app in your phone to read boards in other language and translate from English to the local language for conversations.
I am sure you would have more inputs on this, so please feel free to share your inputs and we would love to include the same with due credits.