I had purchased a couple of Indian outfits that, made out of cotton, covering me from head to toes, and came to appreciate how the loosely fit clothing allowed my body to breathe and the rare wind to cool me down (this is something I do recommend you buy. The clothes cover you, so the danger of sunburn is minimized, and you can even feel some coolness on top of it). I had another advantage--being Asian, I can pass for Indian in the back, and thus minimize trouble. Others do not have that luxury, so I think proper Indian clothing helps women traveling alone stay out of trouble. Do avoid sleeveless blouses, mini skirts, and provocative dressing. Even then, sometimes irritable experiences can not be totally avoided. I experienced no problem traveling as a single woman in most of India, but in the large cities like Delhi, expect to be whistled at at night. I experienced that several times as I passed through parks and other places where a large congregation of men gather. However, I have to admit that except for being a bit irritated, at no time did I feel threatened. But know that it is something that can happen in Delhi, and when possible, do walk with another person or follow a group so that you can minimize this. On the up-side, remember that there are ladies-only lines at train and bus stations, one advantage that I found extremely useful to avoid standing in long lines, and getting the best seats on these transportation media.