Let's start the assembly!
First, take your sachet fabric (not the organza) and your front dieline (that will be the one that is one solid piece).
Cut a piece of stabilizer to match your fabric, spray it, and adhere it to the back. For the template, you can cut away the excess paper around the template shape, then lightly spray the back and stick it onto your fabric.
Carefully cut around the printed (or stitched) dieline to cut out the front of your sachet, cutting through all your layers.