Wrap 'em in blue or green painters tape (delicate), spray on the glue and apply the pattern, and sometimes top it with clear packing tape. Works well with stacks up to 6 or more layers.
Some use bits of thin double-sided tape applied in the external waste area. Some used brads in the waste area. Some apply tape only to the edges of the stack. You could use anything that rings your bell, but sort of remember that you need to get it off the finished piece both top and bottom and have the piece take a finish. That can be a challenge with the thin and delicate stuff, or maybe the top one id just sacrificial. You just have to get the glue residue and tape off, so if it works for you, it works.
Terry