Travel as light as possible. Clothing and laundry are both quite inexpensive.Its better for women to avoid tank tops or short skirts / shorts. The best outfit, especially during the hot summers, is a T-shirt worn with loose cotton trousers.
In India, public toilet facilities are few and far between. Take every opportunity you can to use a clean toilet in places such as hotels and restaurants. Make this a habit wherever you go.
Do not let the beggars hassle you, and do not encourage them by giving them money.
Eat non-vegetarian food only in good restaurants. The meat in cheaper and smaller places can be of dubious quality.
Try to shop only in government handicraft shops. There the prices are fixed and the quality is certified. Bargaining is standard in most places and is enjoyed by all.
In hotels, porters and room service attendants are normally tipped at the end of the stay, though an early tip is likely to get you better service.
Dress codes for religious places can include covering your head, being barefoot etc. Ask, so that you don’t unwittingly give offence.
The sun is strong. Remember to use sunscreen on exposed parts of the body. Wear sunglasses to screen out harmful rays.
Always carry a kit of the basic emergency medicines you might need for diarrhoea, fever, etc. Also, band aids and an antiseptic ointment.
Keep extra photocopies of the relevant pages of your passport. This will be required for Indian permits. Also, keep extra photographs of yourselves. These will be required for permits, filling out forms,etc.