I bought a velvet soft 4 piece set a couple of years ago. I use a double duvet on a single bed. Bought a separate set of single matching fitted sheets which does make it expensive.
I took the elastic out of the double fitted sheet and made myself a skirt out of it, which is lovely to wear indoors in the really cold weather.
I wish they did just more of the three piece sets. Most of my friends use a duvet that is one size bigger than their actual bed.