When most people think about putting up some moulding the first thought is simple mitering. Some mitering is not that simple, sometimes it's not just cutting a piece at a 45 degree angle. What happens if your walls have rounded corners? This is where mitering gets a little bit tricky, but not impossible.
Three pieces will need to be cut for one corner: one piece for wall, one piece for going over the corner, and another piece for the other wall.

This method was just for one corner, a wall with both returns will be five pieces. Hopefully this gives a little bit more insight on how to get those pesky rounded corners.