Here is a comprehensive list of things to keep in mind while you are planning a trip to India.
Pre-travel to India (what to carry, tickets, hotel)
1.Ideally, carry backpacks because they are easy to carry and have enough space.
2. Make sure your suitcases and bags are properly labeled and have wheels            underneath. Remember the idea is the journey to be comfortable.
3. Always have your essential documents – passports, travelers’ cheques               and money handy.
4. If you are in India from abroad you should understand the importance of mosquito repellents. The hot and humid weather Indian weather is ideal for mosquitos to breed. Hence carry mosquito repellents while traveling to India. Odomos is a well known brand available at any convenient store in India.
5.The Rough Guide to India 6, Lonely Planet India, India Travel Guides Paperback, 2006 Country Profile and Guide to India and National Travel Guidebook and Handbook DVD-ROM CD-ROM
Health tips (vaccinations, immunizations)
6. Get yourself vaccinated for Hepatitis A/B, Polio, Typhoid, Rabies, Measles, Mumps and Tetanus. Bring medicines that your doctor has prescribed. Carry a first aid kit and mosquito repellent.
In India
7. Once in India you will have to take extra care of your health. That would mean to carry mineral water along with you. It will take time to adapt to the climate and food here, the hygiene standards also differ from place to place.
8. Roadside vendors selling rubber bands to jewellery are found in plenty in India. Be careful about the products that they sell. Bargain smartly with all and try and get the best possible rates. Do not stick on to one shop, look around and compare prices. Be careful when dealing with guides. Sometimes even they try and cheat. So beware and do proper research before hiring people.
On the move
9. If you’re a visitor from abroad make sure you carry Indian Rupees. The denominations of Indian rupees are 5, 10, 20, 50, 100, 500 and 1000. There are many money exchange centers in urban cities so cash exchange will not be a problem.
10. Do not litter. If you are out shopping or moving about in the city streets you will buy crisps and other eatery to save you from the hunger pangs. Don’t throw away food wrappers on the road. Carry a polybag where you can collect the waste you make throughout the day and dispose it off in a dustbin.
11. Indians hold temples and shrines in high esteem. They are careful not to break any rules and regulation. You should too try and follow their ways if you visit Indian temples.  Dress up appropriately especially when coming to temples.
12. If you are visiting wildlife sanctuaries then maintain discipline by not playing loud radios.
13. Get yourself travel insurance or a medical evaluation plan.
14. Always carry a bisleri bottle along with you. Some of the known bottle brands are Bisleri, Kinley, Aqua Fina and Himalaya. To be absolutely safe you can carry water purifying tablets.
15. Road side food is an absolute favorite amongst Indians. It is everywhere and if on a trip here you would fall victim to these exotic flavors. Infact the ‘dhaba’ and ‘chai ki tapri’ culture are exclusive to India only. But if you come from a land where mosquitoes don’t sit on the food then you stay away from it.
16. If you buy fruits from a local vendor do not forget to wash them.
17. Protect yourself from the Indian heat. Carry with you sunglasses, sunscreen and a hat.
18. Internet and Fax is big in India. Every city town and even villages have cyber cafes. The connections may not be that fast but are easily available everywhere.
19. While on the move it is advisable for you to have duplicate copies of all essential documents. Essential documents can be anything from passports to your travelers checks.
20. Local transport in India is auto rickshaws, taxis and buses. All of these are available outside all hotels. Rickshaws and Taxis charge you according to ‘meter’. They have a car with them which you can refer to before paying the money. Buses have bus conductors who charge you fix fares. Despite of this there are still chances that some rickshaw wala or ‘taxi walas’ will try take more money from you. In such cases negotiate about the money before you take the ride.
21. For your electronic gadgets you’ll need to purchase a converter. The voltage used in India is 220 volts (the U.S. uses 120 volts). You can also use a spike buster which is quiet common in India.
22. If you travel in unhygienic places, if you stop by vendors and eat food or drink water that is not bisleri you are quite likely to catch malaria or diarrhea.
23. You will find pharmacies and chemists shops scattered in everywhere in India
. In case you need a doctor, your hotel can help you with it. Consultation fees is very low, the services are good.
24. To tip or not in hotels is entirely up to you. Although most of the hotels have a service charge included in the bill, it is sort of a tradition to tip in restaurants.
25. Credit cards like Master Card, Visa, American Express and Diners Club are accepted by most of the start rated hotels, shops and airlines.
26. If you are in India and on roads learning to be street smart is of utmost priority. If you are not aware, there are many out there looking to thug you. The first precaution as a foreigner in a strange land you can take is keeping all your documents safe. If you are putting up in hotels then make sure you keep you important papers safe in your bags. Do not forget to lock your bags.
27. Have an Indian friend who has contacts with commissioners, travel agencies basically a man who can get you through when you cant do it on your own. If you want to survive here you got to make sure you are in touch with right kind of people.
28. If you carry your wallet in your pocket keep checking its there.
29. You can be a little smart and carry an “interior wallet” which can be fastened around your neck, worn with a Velcro around the calf/ankle.
30. Be in charge of your own luggage at all times. Guides and porters can be trusted but do not rely on them blindly.
Bargain tips
31. Learn to bargain with conviction. Learn to listen to your instincts especially when it says you are being sold overpriced stuff. Look around 3-4 shops and compare prices before settling down to buy.
Language
32. English is spoken in the urban areas of India so foreign tourists should not have much of a problem. Hindi is the national language of India which is also understood by a wide population. Knowing the language makes your work easier. Although you would be surprised that sometimes even in rural areas there’d be at least one person who can speak broken English.
Driving
33. Your driving license is your identification. So carry it. And if you wish to drive on the Indian roads you can obtain an international driving license through Automobile Association.
Dress code
34. Bring bare minimum: 2 pairs of jeans, 4-5 tees, 1-2 linen shirts and a jacket if needed. If traveling in winters do carry a jumper or a coat. Rest if you need anything you can buy Indian and blend in with the locals. Do not forget to buy sandals here which are extremely comfortable to move around in.
Traveling by train
35. The image of the Indian Railways is poor. People are always full with complaints like difficulties in reservations or that the information is in the national language making it difficult for foreigners and others to comprehend. But what need immediate attention are the unhygienic railway compartments and stations. Avoid traveling in the Second Class.
Shopping
36. There is a wide variety of products available in India. From clothes to furniture to gold and jewellery, you name it and India has it. Each region has its own specialities. The first thing as a tourist you do is find out what is that and then locate where you can get it. Once done with that you can exercise your bargaining skills.
37. If you are planning to indulge in any kind of import export activity then you have to make sure that you have full permissions. You should have a certificate of legitimate sale and permission for export.
Tips for Women
38. Dress Moderately. Revealing clothes are objectionable and can draw unnecessary stares from men.
39. Women with cigarettes are still a big deal in this country. So if your insides crave for a smoke make sure you excuse yourself and smoke in solitude. Atleast make sure the people you are with don’t have an issue with that.
40. If you are traveling alone it is advisable to think before venturing into deserted places. Gather full information before taking a plunge. If you are a foreigner beware of men who would try and sexually abuse you.
41. Travel with bare minimum if you’re going in a local transport. Keep your luggage in front of your eyes all the time. Prefer traveling deluxe buses over state transport if you are going on long trips.
42. You will find many who would try taking undue advantage of you thinking you are a woman. The best way to keep such thugs away is to move in groups. That itself keeps harmful people away. Also take care if al your personal belongings at all time.
Adventure Travel tips
43. Before setting out for an adventure make sure you are fully geared up. If you’re going up north for treks make sure you have warm clothes and the tours are properly arranged.
44. If you are going to extreme down south like Andaman and Nicobar for scuba diving make sure you have all the permissions.
45. Carry a map along with you.
46. Do not litter high altitude places. Conserve the environment. Be eco-friendly
Physical Abuse and many such mishaps
47. There have been many cases in India where foreigners try getting currencies exchanged unofficially in the greed of getting better exchange rates. But as soon as the broker gets hold of the money he vanishes into thin air. Always go for reliable known places like Thomas Cook etc.
48. If ever you get involved in a police matter you are very likely to pay a heavy monetary amount to get out of it.
49. In case of any sort of trouble contact you’re Embassy and the nearest Police Station. The attitudes of police inspectors might be surprising but be patient and do not leave without filing a complaint. If you have an Indian friend who is well connected in India then that is a boon in such situations.
50. If your taxi or rickshaw-wala charges you too much you can note down his number and lodge a report with Deputy Commissioner of Police (Traffic).
51. Sadly, there have been cases of deaths of foreigners who were cheated before they were killed or even females who were here on holidays and were raped and murdered. Keep in mind that such extremes only happen when you let a stranger in your private space. Do not drink too much and move around in groups always.