I have always washed clothes in cold water, never really thinking about the fact that it was saving money. I did it because we would run out of hot water, and none of us enjoed when the hot water in the shower turned cold on us. After we got a new hot water heater I continued to wash clothes in cold water. I have only recently begun to try to learn how to save money, but in that respect I was being frugal and didn't even know it.
Sometimes I add a little clorox to brighten my whites but the clothes always come out clean.