Decorate cake. Use fondant roller with orange guide rings to roll out medium orchid fondant 1/8 in. thick. Use ribbon cutter with 1/4 in. spacer to cut out fondant ribbon, 20 in. long. Use damp brush to attach ribbon to bottom of 6 in. cake. Use knife to trim, if necessary.
Prepare thinned fondant adhesive. Roll reserved white fondant into three balls, 1/8 in., and two balls, 1/16 in. Use brush and thinned fondant adhesive to attach balls to center of cupped blossoms. Use brush and thinned fondant adhesive to attach flowers and leaves to center of 8 in. cake. Hold in place until set, about 1 to 2 minutes.