One is to cut up cereal boxes. Usually the inside is blank. The large sections I give to my 3 year old for water colors or drawing. The sides I cut up and use for grocery lists. Why? My motivation is more at keeping things out of the landfill than saving money, but I'll take that to. Once you are frugal, it can be hard to stop.
Anyone want to share an "extreme frugal" tip today?