Be ready to be honked at.
Get stuck in congested traffic where no one can move. Keep loads of buffer time.
Triple check 360 degrees around you before crossing a road even if you have the right of way.
If you are traveling in an auto-rickshaw or bus hold tight. They, especially, drive crazy. Even locals are pissed.
Book a hotel on a well known site and read reviews before booking. If a hotel is cheaper then there is a reason…think. Either the location is down market or service or quality of the hotel is not good.
If you are in an area where there’s not much happening around or internationals around, avoid wandering alone or late nights.
Prostitution is legal that is why, I think, that there are so many rape cases in India. So, be careful.
What you won’t find easily in India:
Creeps; because people are friendly but still be careful.