How to Use Procreate's Reference Layers! Procreate Tutorial! Using reference layers in Procreate are so helpful for creating digital art, but they are often overlooked. In this Procreate lesson, learn how to use reference layers to make your digital art pop. Whether you're a beginner looking for Procreate lessons, or an advanced user looking for Procreate tips and tricks, this Procreate technique will make you want to grab your iPad to create some digital art!