I posted this on the blog, but decided to repost here. I am self taught in applique. I got this idea from the instructions to my Dear Jane BOM. I used it to make hundreds of leaves in 3 sizes for the border of a quilt.
"I use freezer paper on the wrong side of the fabric, too. I use a small running stitch in the seam allowance on outside curves, paint with starch, pull the string to gather the curve and then iron. It makes the outside curves easier to get smooth. Clip the inside curves, paint with starch and use the tip of the iron to push the clipped portion to the curve of the piece. I use Elmers School Glue. I went to Michaels and bought a kit that had a bottle and some very fine tips. I poured the glue in that squeeze bottle, topped with one of the tips. It comes out in a very fine line or small dots. Use the iron to dry the glue when the applique is where you need it. The school glue will allow you to pull up a piece and reposition if necessary, or if you forgot to put one piece behind another, etc. Just reglue and iron down again. the school glue comes out in the wash and is not too stiff. Use a large headed pin to plug the tip or to clear it if it becomes plugged. Hope this helpes "