I have used the dryer sheets in yet another method of applique. Place your shape face down on the dryer sheet, stitch around the shape, trim way excess, split the back open and turn. Push the edges out and press flat on the stitch line. Trim the dryer sheet to about 1/4" all around and then applique. I haven't tried it on leaves, but it should work.
WARNING: Be sure to place an old piece of fabric over your ironing surface as there will be a residue builtup from the dryer sheets. No need to ask me how I learned this! I have graduated several times from the School of Experience.
Suzanne