As a rule of thumb, pay attention to what local people are doing, and try to blend in as much as possible.
Appropriate Attire -- In India, your attire will often signal your status, and casual dress will make it more difficult for you to elicit respect. Women should wear loose, cool clothing that covers up as much as possible. Exposed flesh suggests that you're too poor to dress properly, or that you're shameless about flaunting your body. Transparent and tight clothes are also considered shameless; the more you can disguise your shape, the better. Men should avoid short shorts, which are considered bizarre outside large cities or beaches. Women visiting public beaches should be as discreet as possible and avoid sunbathing on empty beaches. In mosques and Sikh gurudwaras you need to make sure your head is covered -- a worthwhile purchase is a scarf you can keep in your bag at all times. In certain Hindu temples -- particularly in South India -- a man may be required to wear a lungi (a long piece of cloth worn like a kilt) and remove his shirt. Always check what others are wearing before venturing in, and approach slowly so that someone can intervene before you offend the sanctity of the holy sanctuary.
Shoes -- Shoes are never worn in places of worship -- you are even required to remove your shoes when entering certain churches. It makes good sense to wear a pair of comfortable, cool, and cheap sandals, like flip-flops -- they're easy to remove and unlikely to be stolen; leaving a pair of expensive shoes outside a temple or mosque is not a good idea. However, you can leave your footwear with an attendant outside for a tiny tip (Rs 2-Rs 10) -- and you will almost certainly get them back. Some museums and historical monuments may also require you to remove your shoes, and you should extend a similar courtesy when entering someone's home. In Sikh gurudwaras you are expected to wash your feet after removing your shoes.
Touching -- Public physical contact between men and women is far less acceptable in India than in other parts of the world. Some Indians -- particularly those who live in the larger cities and have traveled -- understand that Western men and women may shake hands (or even kiss) as expressions of social friendship, but you should be cautious of casually touching an Indian woman in small towns and villages. Even the slightest touch can have a sexual connotation. Remember that it is not unusual to encounter someone who has never seen a foreign face; attempting to shake hands with such a person may prove overwhelming to him or her. When in doubt, fold your hands in front of you, bow your head slightly, and simply say "Namaste" (pronounced nah-mah-stay). Traditionally, Indian people use the left hand as part of their toilet routine. Consequently, the left hand is considered unclean, and you should only offer your right hand when greeting someone. Don't touch a religious object with your feet or left hand. People generally use the right hand for handing over or receiving cash as the left is considered inauspicious. If you wish to put your feet up in a train or other form of public transport, take your shoes off first. If you are booked on a higher berth and don't want to leave your expensive shoes at floor level, put them in a plastic bag and take them up to your berth with you. If you inadvertently touch/kick someone with your foot, it's customary to extend an apology. In fact you will notice that in some parts of India, if an Indian accidentally touches you with his foot, he will immediately follow that up with a hand gesture that first lightly brushes you with the tips of the fingers and then brings that hand up towards his chest or forehead. Even if nothing is said, this constitutes an apology.
Avoiding Offense -- Indians love to discuss all manner of subjects, and more educated individuals will readily get into wonderfully heated debates -- which may be among your most memorable moments in India. Do exercise discretion, however, when trying to understand the enigma of India's overwhelming poverty and the caste system. Don't harshly judge or criticize things you don't understand fully; Indians can be quite passionate about their nation and will defend it unequivocally. Words are seldom enough to offend an Indian, but avoid strong swear words in the context of an argument or insult. And always be considerate and humble when entering a place of worship.
Eating & Drinking -- When eating at someone's home, remember that it is not unusual for the woman to cook and spend the entire evening serving. Don't interfere with this custom, and don't venture into the kitchen -- especially if you're a man. Foreign women will generally be treated as "honorary men" and should dine at the table unless an alternative suggestion is made. Note that the above rules apply more in orthodox homes and to a much lesser degree in modern city homes, where in fact it is polite to offer help, even if the answer is negative. Use only your right hand when eating (unless knives and forks are used), and follow the lead of your host when you're unsure. Don't be afraid to ask about the food, but you must be quite firm about not drinking water (unless it's bottled) and being mindful of salads and cut fruit . Consider bringing your own bottled water with you.
Mind Your Temper -- When confronted with bureaucracy and IST (Indian "Stretchable" Time), maintain your cool. Schedules are bound to go awry and government offices are notoriously inefficient, so there's simply no point in losing your temper. You'd be well advised to adopt a similar attitude with wealthy and "important" Indian men who, as a matter of course, cut into line. Rather than fly into a rage, point out the lack of consideration firmly and earnestly or, better still, smile beatifically and practice a meditation technique.
Photography -- Photography at airports or military installations is strictly forbidden, as it is at all burning ghats (crematorium sites) in Varanasi. Note that carrying a camera to attractions throughout India will add significantly to your entry fee. In touristy areas don't be surprised if people offer to be photographed and then demand payment.
Saying Yes Even When the Answer Is No -- When you ask for directions, people will often send you in the wrong direction rather than admit they don't know the way. Try not to ask questions that require a yes or no answer, because you will almost always only hear yes. In other words, rather than ask, "Is this the way to the Gateway of India?" try, "Can you tell me the way to the Gateway of India?" If the person seems hesitant when giving you directions, verify that you are going the right way by asking someone else a few minutes down the road.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.