Before I went to India, I researched on the internet on the the dos & don'ts for girls on what to wear. Since it's a mostly conservative country (although you'd think otherwise since even the older women bare their midriffs when wearing saris), shorts and too much decolletage is a no-no.
And since our trip was scheduled in the heart of summer, I was worried that I might faint from heatstroke if I wore pants all the time. I dread wearing pants even here in Manila!
The solution were cotton pants, cotton shirts and surprisingly, the local dress salwar kameez. They kept me cool (cool as in temperature, not status) in the dry heat of the indian sun.
Whenever visiting a cultural country, it is often best to try and wear their local dress as long you won't offend anyone with it. The way and material in which they are made are usually the most apt for their climate and most acceptable. :)
In a nutshell, here are the dos and don'ts:
• don't wear shorts or anything above the knees
• do wear cotton loose long skirts, harem pants or cotton pants for summer, and jeans for winter months
• don't wear tank tops or spaghetti straps ever
• short sleeves are acceptable for summer, although winter months wear long or 3/4 sleeved tops
• wear/bring cotton/silk scarves. They are handy to cover your chest area if your shirt is a bit too low cut, and also used to cover women's heads when they enter certain temples
• wear comfy shoes and sandals!