Those are meant to be appliqued. There are literally hundreds of ways you could use them. For example, a holly wreath. (I would add red yoyos for the berries) Many patterns call for 2 or 3 leaves goind from a common point, again with yoyos at or near that point. I can't tell what the marks on the lower one mean, unless it is intended to be backing for a 3D leaf. (Sew right sides together, clip, make a cut in the middle of the backing piece, turn right side out, hand stitch the backing closed, attach to background by quilting along the vein lines . Again, add Yoyos at the base of the leaf.) Another way to do this is to make the backing from 2 pieces sewn on the center line, but with a gap in the seam through which the birthing can occur.