I can say with complete certainty that I have never ironed a sheet in my life. This isn’t that kind of housekeeping blog. :)
With a fitted sheet, once you put it on the bed, it stretches out pretty taut, and then you sleep on it, and so I guess I never felt the need. Plus, when you make your bed, no one can see your wrinkled sheets.
As for duvet covers, ten minutes in the dryer with a damp washcloth takes out most of the serious wrinkles, and again, once it’s spread out on a bed, the wrinkles are kind of incidental.