2, buy a long scarf in the local area, it is very cheap, twenty or thirty RMB is not bad, and there are many styles. It plays a very important role in preventing dust (the air in northern India is very dirty, even worse than that in Beijing) and preventing cold (it is usually 4-22 degrees in winter in northern India, with a large temperature difference in one day). If you take the train sleeper and car sleeper with ordinary seats, you can also berth them (generally not very clean).
If you are a low-budget backpacker, please bring a sleeping bag with an inner liner. The sheets in small hotels are sometimes not clean.
4. Go to the "foreigner ticketing center" of the big city railway station and buy all the train tickets for your trip (it is easy to change the ticket and refund it). The pre-sale period of Indian train tickets is very long, and your visa stay will be extended. Delhi, Kolkata, Mumbai, varanasi and other big cities with concentrated tourists all have rooms dedicated to selling tickets for foreigners.
5. Diarrhea usually comes inadvertently at some point. Don't take medicine indiscriminately. The best way is to fast, eat only bananas (extremely cheap), rest for two days, and the average person will be fine. If not, see a doctor immediately.
6. Indian swindlers are not as terrible as China swindlers. You just have to turn a deaf ear to them, go ahead and get rid of them.
7. Besides eating, you have to bargain hard for staying (hotel), traveling (all kinds of motorcycles and taxis) and wearing (all kinds of beautiful handicrafts). Come on, Indian businessmen won't be angry.
8, girls, prevent Indian men from stealing oil-short skirts and sleeveless things are really free. But there is really no need to "don't talk to Indians", otherwise what are you doing there? To be honest, chatting with Indians is very interesting. The educated class will be more reserved, but if you get along with them, they will be very enthusiastic.
9. Try the north and south food. Personally, THALI in Gujarat and BIRYANI (curry rice) in the south are delicious. If there is fish in the restaurant, you must eat it, because few restaurants have fish, and it will always be a fatal chicken. You can buy some cucumbers to supplement vitamins when you pass by the market.
In big cities or tea garden areas, you must have afternoon tea. A pot of good tea+two delicious cakes is less than 15 RMB.
Supplement: I agree with the answer given by @ I forgot lassi, this is the magic of yogurt. This is definitely the best food in India. Don't miss it if you see it. In addition, Indian ice cream, that is, Ma Sala spicy flavor Kulfi, is also very good and delicious.
In the case of too much rice flour and milk sugar, although there is less meat, there is still the possibility of getting fat, so we must be cautious.
10, really tired of curry, go to Tibetan community, you can eat noodles, noodles, beef, flower rolls, steamed dumplings and even stir-fry.
1 1. If the US dollar runs out, UnionPay cards can withdraw money from HSBC, and you can check the address of HSBC in the city where you want to go.
12. Prepare a smart phone, buy a Vodafone or AIRTEL SIM card locally, and buy 1GB or 2GB of EDGE traffic every month, which is enough for you to send emails to your computer, browse the web and chat QQ, but only 10 ~ 20 RMB. 3G is too expensive, and there is little WIFI in India.
13, it is still very important to have a good guidebook, especially since there are more people here than in China, and it is easy for you to get confused about the environment.