U lucky basterds. Lol
Anyway, little tidbits of advice, that long post above was seriously good advice.
You will indeed hear Yes a lot because they tend to regard a close enough compromise as pretty darn acceptable. Too much time on their hands to take long ways around things, you might not have that much so be very specific about what you want and be skeptical in accepting a general answer.
About ppl trying to sell you shit on the streets etc, just don't look at them. It will discourage them. Waving them off politely with your hands without making too much eye contact works too. A little rude but otherwise you will spend forever fending them off, especially in old cities.
With water, try to stick to decent bottled water but filtered, boiled & cooled water is as good. Try to not eat raw foods for a few weeks there. Get used to the bugs first. Insist on hot cooked food until your system adjusts. fried can be good in that regards except for cheap vendor using rotten veggies, so buy your fried where you feel more certain. Eating where the locals seem to be eating is not a bad idea as far as the place seems alright to you too. South Indian eateries are usually run very clean, rather strictly clean by tradition than anything else, so dosa, idli, sambar, vada focussing restaurant is rather safeish. Again, let your system adjust b4 you go trying more
Again, with rickshaws, taxis n all, look it up beforehand where you want to go and don't feel shy about asking someone a out the best way to get there before hailin your rickshaw/taxi. Ppl's directions can be hard to wrap your head around sometime, iftey tell you it's past 2 bridges/flyovers and red lights, well, those are their way of punctuating the route. Gol chakkar (roundabout), red lights, flyovers, hills are all route punctuations. And they will use slightly different terms for them everywhere you go.
Personal space on public transport can be an issue, usually they kinda understand the issue foreigners have with that and give you space so don't step back on taking reasonable space or you will lose it, lol. Especially on trains.
Not a bad idea to buy a light decent chain to shackle your luggage to something fixed on trains and buses etc. It's easy to fall asleep on long journeys and that's exactly what the locals do too. And they lock their bags.
If you don't intend to be unapproachable, then ditch the sunnies when not required. It can make a difference. It can be quite dry up north and humid down south so be prepared.
And yeah, common sense
Gl there bribie, btw, I heard the banjos play
