Alot in India depends on what you are comfortable with.
You will also find vast differences in culture, dress and whats considered personal space throughout this beautiful country.
Being Indian myself, I visited Mumbai and Chennai on business.
My experiences are as follows:
1. Nothing is for free, even if they tell you its free. Even someone pointing you in the right direction on the street expects something, as much as the guy who offers to push your trolley out the airport.
2. Beggars don't take no for no answer. Take this seriously, take out a few hundred rupees in front of a mob of street kids and they will follow you from one province to the next right to your hotel room.
3. Taxi drivers are out to take you for a ride. They will try to use a meter and drive you around town, eventually arriving where you wanted to go. Distance from point a to point b is 8kms, including driving around mumbai for an extra 6kms, means you pay for 14kms and not 8.This is a well used trick to get you to pay more.
4.Most drivers are pretty useless at knowing where places are, most will get "lost" even though they say they know where a place is when you get in the car.
5.Try to always agree the price before you get in, and be firm.
6. Foreigners can be spotted miles away, even if you wear the same clothes, and blend in, even if you speak the local language, you WILL stick out.
7. Always, ALWAYS bargain prices. I have been into shops and get told a price, and the shopkeeper will tell the salesman, he should have told me a higher price, cant he see I am a foreigner. You can negotiate a price from 1000 rupees to 80 by just walking out the door and walking out and away from the shop, the chap will follow you and the price gets cheaper.
8. When you go into shops in the markets, get ready for the guys to unroll hundreds of rolls of fabric for you, sarees, silk etc. They don't take no for an answer and will start unrolling which can be overwhelming. Dont waste their time, if you know what you want in which colour, ask for that specifically and say you only want that. If you tell a guy you looking for a black 2m fabric and he says 600 rupees, and you say 70, then he says 500 and you say 70, then he says okay, pay 300 and you say 70, then he says 200 is the lowest, and you say 70 and start walking away, and he comes back to you and says okay, take it for 70, and you say NO. Consider the guy insulted, hell I would be if i was the sales guy also.
9.3 star hotels in India are the equivalent of 1 star south african hotels, 5 star is on par with our 3-4 star south african hotels.
10.Always smile and nod and say hello at the hotel, it can net you amazing service, and keep some tips on hand for the bellboys, door guys.
11. Its hot, not Durban Hot, Hotter, and humid.
12.Drink bottled water. I normally drink tap water extensively in other parts of the world that I have travelled to, including 3rd world places and have never had an issue. India is one place where i would not chance it.
13.Do not buy bottled water from "bottled water" people who walk around selling them. They collect the empty bottles and lids, refill with tap water, put on the li and use a lighter to melt the twist top seal back in place making it look like its new water, when in fact it isn't. People may tell you this doesnt happen, but I have seen it.
14.Dress modestly. India is patriarchal and ladies dressed immodestly get cat called, leered at and even groped in the bazaars. I am a man, so I never had issues, but had to caution a female colleague to keep it decent so as not to get us into a situation.
15. People are poor, really poor. You have not seen poor people like there are in india. Be prepared for that, because it can affect you seeing abject poverty and desperation in little kids eyes. It truly is sad.
16.Be prepared to pay tourist prices everywhere. All attractions have a price that says Indian - 10 rupees, non-indian- 100 rupees. I had many arguments about this, in fact refusing to visit some places because they wanted to charge me the non-indian price even thou, i am indian, and every indian worldwide, hails at some point from india originally.
17.Many places are ridiculously filthy. People will spit anywhere, even onto your foot if you dont have closed shoes. Closed shoes, closed shoes, closed shoes. Unless you like another ous tongue grease on your foot.
18.Mumbai is like New York, people are unfriendly and nonchalant and most are trying to get you, because you are a tourist. as you go more and more south, you will start to see real indian hospitality, because the people are less tainted by globalisation.
19. There is no such thing as personal space. an oke will stand flush against you in a queue for no reason whatsoever, and then answer his phone. its weird. Having a face like mine helps with this problem, people think I am dangerous most places.
20.The airport process can be confounding, and seems not to make sense, so arrive early, get to you gate and when you see everyone else move, just move. Chances are they told 2 people the gate has changed and didnt bother to tell anyone else. You will miss your flight.
21.India is rich with spice and flavour. The way vegetables are cooked in India is unlike yoi have ever tasted before. You will eat vegetables you never eat here, because of how they are prepared in india, don't rob yourself of this.
22. You don't need a medical script for prescription meds in india, so if you get sick, go to a pharmacy and get an antibiotic over the counter.Also, if you take chronic medication here for heart disease, high blood pressure or anything else. You can buy a years supply there without a script for much less than you can here. If you are worried about quality, dont. Many large international drug companies manufacture the meds in india and other 3rd world countries. Its cheap and you dont need a script, save some money, just be mindful of expiration.
23. Usually, things in malls are not cheap, not in general. The price of an adidas shoe in a mall in mumbai is more on par with the price here, so why take the hassle and lug it around india and then back here. Stuff on sale is much cheaper in big name shops when sales are on, so shop at those stores. Unless you are mr moneybags, ignore this point.
If i think about anything else, i will put it up. but thats what i remember now.
It is really something you must experience once in a lifetime, indian or not.
My mum has been about 8 times, and even visited our ancestral homestead.
I know where i came from (which is cool), and can now apply for dual citizenship, not that it really has any benefits, except maybe not requiring a visa to emigrate when the shit hits the fan here and gets like Zim.
Enjoy.