Many applique designs have templates provided in the download. If not, there is an easy way to create a template using software.
Templates are really useful if you stitch applique designs. One reason is that they allow you to create a guide for cutting out the applique piece. Pre-cutting your applique pieces saves a lot of time you would otherwise spend removing the hoop, trimming excess applique fabric, and re-applying the hoop. All you need to do is add some temporary spray adhesive or glue stick to the back, finger-press it in place, and continue stitching.