International airports operate the conventional green and red channels, with officials liable to carry out a sudden spot checks on passengers passing through the green channel. If carrying items of high value such as cameras, laptops and the like for your personal use during your trip, you may be asked to fill in a Tourist Baggage Re-export Form (TBRE) when you enter the country, which allows you to bring items into India free of duty, provided you take them back with you when you are leaving.
The normal free allowance while flying he government-owned Indian Airlines is 30 kg in Economy and 40 kg in First Class. For the private airline operators it is 20 kg in Economy and 30 kg in First Class, where available. You can carry only a single piece of hand baggage (within certain size specifications) on domestic flights.
Airport departure tax is usually included in your international tickets and does not have to be paid at the airport.
Yellow Fever - Vaccination Certificate is required if arriving from an infected area.
Cholera/Typhoid - Innoculation recommended.
Malaria - No certificate required, but advisable to have a course of pills.
Tap water is not purified for drinking. Unless you have access to a water filter, or are sure water has been boiled, it is safer to stick to bottled water. Avoid ice in your drinks outside your hotel. Avoid ice cream or food sold by roadside vendors, uncooked or undercooked foods, fruit or vegetables that cannot be peeled.
The majority of India works on 220 volts AC 50 Hz. However, it is possible that certain areas have DC supplies and it may be a good idea to check before using electrical appliances. Socket sizes vary, so it is well to take along a set of plug adaptors.
Note: You will probably need to get an adapter for your devices. It's pretty easy to get "all-in-one" adapters that you can use to plug your device's power chord into before plugging into the power supply.
India is a "shopper's paradise". Due to the patronage received over the past centuries, different types of arts developed in different areas. Silk, brocades, carpets, rugs, brass-ware, textile, miniatures, wooden carvings, furniture and jewelry are great bargains. Returning or exchanging of goods once bought is not entertained. If you desire, the shops will export your purchase to your address. Most shops that sell to tourists welcome the major credit cards, some even except personal cheques.
Hotels, restaurants, taxis, etc., in this part of the world, do not include a tip in their bills. It is not obligatory to tip, but expectations are there.