1. Roll fondant 1/8 inch thick. Make a practice bow using these measurements; once you have mastered these steps, modify the measurements for your own cake design: Cut two strips 1 inch wide x 6 inches long for loops and one length 1 inch wide x 2 inches long for center.
2. Make two loops: Fold strip over to form a loop, aligning ends. Brush ends with a damp brush. Pinch ends slightly to secure. Stand loops upright on side to dry. Make a bow center: Wrap length around your finger to create a loop; brush area to be seamed with a damp brush; overlap the ends slightly and press together to secure. Stand bow center on its side to dry.
3. Insert the ends of two loops into center; secure with dots of icing if necessary and position on cake.
Found at Wilton.com