I recently used icing sheets for the first time. I let the royal icing on the cookie dry completely before applying the icing sheet. I thought I had read somewhere that to use the icing sheet I just needed to peel off the backing and it sticks to the cookie, but that didn't happen. I ended up thinning out some royal icing to use as a "glue". I put a thin layer on the back of the icing sheet before placing on the cookie. This seemed to work, but I got some bubbling up on some. Would love any advice or tips on how to best work with icing sheets.