You should expect to have very warm to hot days during which the air gets particularly humid. Pack lightweight cotton or breathable fabric clothing that is loose-fitting and not revealing. Longer skirts for ladies are more comfortable than jeans since they allow for airflow around the legs. Linen pants and shorts for men and women will be more suitable for the weather. You can also find local stores that sell or custom-make traditional Indian clothing so visitors not only have souvenirs but a practical outfit with fabrics that fit the climate. Indian culture is somewhat conservative, so dressing modestly, keeping covered from neck to knees, is appropriate.
Plan for lots of walking, some on dusty streets. You'll want to have at least three pairs of shoes that you can interchange, one being light enough to carry in your day bag and use in the later day when your feet need a break. Make sure they are easy on-off shoes, as entering homes or temples and other sites will require you to remove your shoes frequently. Also consider bringing or buying a hat or light scarf to cover your head from the heat as well as when visiting sacred sites.
Carry toilet paper or small packages of tissues with you when you're traveling. In-ground toilets are most common in India, not Western-style toilets, and most don't supply paper. Put a small bottle of antibiotic hand sanitizer in your bag as well for quick washes in places that may not have public sinks or water available. A small flashlight that fits in your bag can be useful during rotating blackouts in various cities or sections of the city where you're staying.
If you are doing your own laundry while you travel, pack small containers of hand-washable detergent like Woolite. Sunblock, mosquito repellent, Tylenol and Immodium or stomach-settling over-the-counter medicines will serve you well. Make sure you pack daily malaria pills and any other medicines recommended by your vaccination agency. Bring water in disposable bottles that you can carry during the day and drop off as you finish them. Non-melting snacks or packages of nonperishable food like tuna can provide a break from Indian food if you need it.
Plan to hold all your travel documents on your person when you travel about. Your passport, visas, money and credit cards should be in a travel-worthy pack that is easy to carry. AAA and other travel stores like Travel Smith sell various holders that fit underneath your clothing or on your belt to tuck away inconspicuously but keep your documents together.
