Cut a rectangle of silk 8 to 12 inches long and 2 to 5 inches wide. Note that the grain of the fabric should run vertically along the width so the fabric's surface looks similar to that of real petals.
Using a needle and thread, sew a running stitch along 1 long side of the rectangle (1/4 inch from edge), and then pull thread to tighten the fabric into a bunch. Hand-stitch center, and knot it off.
Cut a smaller rectangle of silk 6 to 8 inches long and 1 to 2 inches wide. This time, cut so the grain runs horizontally. Create a fringed edge by removing a few horizontal threads at the top of the rectangle.
Sew a running stitch along 1 long side of the rectangle (1/8 inch from edge). Pull thread to tighten fabric into a bunch. Hand-stitch center, and knot it off. You will have a small rosette.
Snip small curved triangular shapes from poppy to create defined petal shapes. (Alternatively, cut fringed petals.)
Place a button in the center of the rosette, and then place rosette in center of poppy. Sew button and rosette onto poppy, and knot it off.