To mount a photo onto ground paper, apply adhesive to the back of the photo rather than to the ground paper to which the photo will be attached. After arranging the photos in the way you want them on the ground paper, using a pencil, lightly mark around the corners of the photos. After applying adhesive, attach the photos to the ground paper inside the pencil marks. I learned this from reading Scrapbooking for the First Time, by Rebecca Carter.