Anael...a couple of tips I picked up in an appliqué class using butcher paper, or paper with wax on one side. Stack two pieces keeping the non waxed side up and iron them together, smoothing out all bumps and air bubbles. Trace your pattern on a see through paper, and iron it onto the wax side of the butcher paper. Cut the shape out of the wax paper and remove the see through paper pattern. Now iron this wax side down onto the wrong side of the fabric and cut the fabric around it leaving enough fabric to turn under. Using the very tip of your iron, turn the fabric over the butcher paper template. At this point I brush a light glue like Sew Stable on the seam allowance and iron it dry. School glue thinned with a little water might work but I've never used it. Now remove the template, it won't be too stuck to the paper, and your shape is ready to stitch to the block. It's kind of like PP and will give you a very precise form but it does take a little work. You can reuse the wax paper template up to 10 times if necessary. If you sew these on with a machine, use a very small thread like a silk 100 weight and your seams will all most disappear. By hand the finer thread works best too. You can probably find this process on line and see all of the steps in picture. Give it a whirl. You might be pleasantly surprised with the results.