India is a country with different climates, but on the whole it will be warm and at times you can feel the humidity. The north Indian destinations will be definitely cool from December to February and woollen jackets can keep you warm. Otherwise, lightweight shirts and trousers will be sufficient for your entire trip. You can either plan for an in-house laundry in hotels or local purchases, both will be cheaper than your homeland. If mosquitoes are found to be prevalent in the places of your visit, full sleeves can keep you safe.
The customs and practices in India vary from place to place. Your itinerary may include temples, monuments and palaces. It is recommended to follow the dress code and procedures of the locals as a gesture of respect. Other than the above, wind proof jackets and dark coloured costumes for a wild safari, slip on sandals for temple visits and dresses covering upper arms and legs for ashrams are suggested.
The list of personal items you can bring from your homeland can be an inflatable pillow, a torch light, electrical surge protectors, a small handbag which can hold your camera and other smaller needs.