I like to have two square pillows at the back, one on each side of the bed, this makes it extra comfortable if, like me, you like to sit up and read in bed, and then two rectangular pillows on each side, as the regular pillows. They make up like blankets so you can achieve that lovely old-fashioned bed look without the bother of three blankets. It's nice to have a square one because it's nice to sit up in bed with a big pillow behind you.