FIMO polymer clay is an oven-hardened craft clay known to be specially suited for projects involving a high degree of detail, due to the clay's stiff firmness. FIMO is an excellent craft product to use in the creation of model flowers, whether you're making generic blooms or trying to imitate the appearance of a specific type of plant.
Create the centre of the flower, if it is visible. Most of the time, this requires forming a small piece of yellow or black clay into a ball, then flattening it slightly by pinching it between your fingers. If you like, give the piece texture by pressing it against some coarse fabric, like a sweater.
Make the flower's petals. Form small pieces of coloured FIMO into balls, then flatten with your fingers. Shape by trimming the flattened sections with scissors. If you want to give the petals are particularly delicate look, dip your fingertips in ice water (this will keep them from melting or sticking to the clay), then squeeze the petals until they're almost as thin as the real thing.
Wrap the petals around the centre. For roses or other flowers with many layers of thin petals, create several layers of petals. Place them side by side and stagger the positions of the petals for each layer. Blend the bottoms of the petals into the clay of the round centre piece.
Add stamens, if your flower has them. Roll a small amount of yellow or white clay into a long, thin snake, then cut short lengths of this piece to make the stamens. For each stamen, curl the very end of the piece down to create a slight nub at the end of the stalk. Attach the other end of the stamen to the inside of the flower by poking it into place with a needle, toothpick or bamboo skewer (depending on the size of the flower).
Make the stem and attach it. Roll green clay into a snake (thicker than the stamen pieces) and press one end of it against the bottom of the flower blossom. Blend green clay up to partially cover the bottom of the flower, imitating the green portion of a bud. Trim the stem to your desired length.
Bake the flower according to the instructions on your FIMO package.