Layering and cutting are two different things. When you layer a shrub you leave the branch attached to the parent plant. Bend it down to the ground and anchor into the soil with a metal pin or sit a rock on top of (Before you do that scrape a wee bit of bark away from where the branch will be in contact with the soil). Cover and leave for a year then check to see if it has rooted, if it has you have a new Pieris otherwise leave longer. Some plants layer themselves, have a hunt round your Pieris and see if it has already done so.