Filling up drinking water bottles from a street pump in Calcutta
Photo ©Ingrid Booz Morejohn
Taxis from airports: use the prepaid taxi offices in the airport for a set fee and don't negotiate with the driver yourself.
Money: change a quantity of money into a stack of 5, 10 and 20 rupee bills. Your hotel will do this for you for a small fee. Small bills are essential for tipping whoever helps you with a million small things. Spread these around and be generous.
Read: as much as possible before you go or visit any one of the many excellent bookshops and stock up on good quality English language books on India. Penguin India and Oxford University Press all have cheaper editions of their numerous Indian titles published and for sale in India. A big savings on what the same book costs in Europe or US.
Toilet paper and wetwipes: sounds ridiculous but these things are essential and very useful. Can be hard to find when you need them.
New Delhi Jelly Belly: such a boring subject but such a pain when it strikes! Most likely unavoidable to a greater or lesser degree but be careful with what you eat, no ice, nothing with water added unless you are absolutely sure it is purified water, no unpeeled fruits and vegetables and keep your hands clean. You should even keep your mouth closed in the shower. Ugh. As the above picture illustrates be extra careful when buying bottles of water. Always check the seal and make sure that it is an original seal and not a refilled water bottle.