Prepare a bag with tip 12 and a bag with tip 150 (104 is optional) with stiff consistency royal icing.
Hold decorating bag at 90° to flower nail. Pipe tip 12 ball on flower nail.
Using tip 150 (104 optional), pipe several upstanding petals in center of ball with a jiggling up and down motion, then circle them with ruffled petals.
As you continue piping rows of petals to cover ball, turn narrow end of tip farther out. Pipe last row of petals at base of flower with tip straight out.